mirror of https://gitee.com/openkylin/linux.git
176 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Andrey Konovalov
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7f0a84c23b |
kasan: change report header
Change report header format from: BUG: KASAN: use-after-free in unwind_get_return_address+0x28a/0x2c0 at addr ffff880069437950 Read of size 8 by task insmod/3925 to: BUG: KASAN: use-after-free in unwind_get_return_address+0x28a/0x2c0 Read of size 8 at addr ffff880069437950 by task insmod/3925 The exact access address is not usually important, so move it to the second line. This also makes the header look visually balanced. Link: http://lkml.kernel.org/r/20170302134851.101218-6-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Konovalov
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db429f16e0 |
kasan: simplify address description logic
Simplify logic for describing a memory address. Add addr_to_page() helper function. Makes the code easier to follow. Link: http://lkml.kernel.org/r/20170302134851.101218-5-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Konovalov
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b6b72f4919 |
kasan: change allocation and freeing stack traces headers
Change stack traces headers from: Allocated: PID = 42 to: Allocated by task 42: Makes the report one line shorter and look better. Link: http://lkml.kernel.org/r/20170302134851.101218-4-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Konovalov
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7d418f7b0d |
kasan: unify report headers
Unify KASAN report header format for different kinds of bad memory accesses. Makes the code simpler. Link: http://lkml.kernel.org/r/20170302134851.101218-3-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Konovalov
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5e82cd1203 |
kasan: introduce helper functions for determining bug type
Patch series "kasan: improve error reports", v2. This patchset improves KASAN reports by making them easier to read and a little more detailed. Also improves mm/kasan/report.c readability. Effectively changes a use-after-free report to: ================================================================== BUG: KASAN: use-after-free in kmalloc_uaf+0xaa/0xb6 [test_kasan] Write of size 1 at addr ffff88006aa59da8 by task insmod/3951 CPU: 1 PID: 3951 Comm: insmod Tainted: G B 4.10.0+ #84 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x292/0x398 print_address_description+0x73/0x280 kasan_report.part.2+0x207/0x2f0 __asan_report_store1_noabort+0x2c/0x30 kmalloc_uaf+0xaa/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x7f22cfd0b9da RSP: 002b:00007ffe69118a78 EFLAGS: 00000206 ORIG_RAX: 00000000000000af RAX: ffffffffffffffda RBX: 0000555671242090 RCX: 00007f22cfd0b9da RDX: 00007f22cffcaf88 RSI: 000000000004df7e RDI: 00007f22d0399000 RBP: 00007f22cffcaf88 R08: 0000000000000003 R09: 0000000000000000 R10: 00007f22cfd07d0a R11: 0000000000000206 R12: 0000555671243190 R13: 000000000001fe81 R14: 0000000000000000 R15: 0000000000000004 Allocated by task 3951: save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_kmalloc+0xad/0xe0 kmem_cache_alloc_trace+0x82/0x270 kmalloc_uaf+0x56/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 Freed by task 3951: save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_slab_free+0x72/0xc0 kfree+0xe8/0x2b0 kmalloc_uaf+0x85/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc The buggy address belongs to the object at ffff88006aa59da0 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 8 bytes inside of 16-byte region [ffff88006aa59da0, ffff88006aa59db0) The buggy address belongs to the page: page:ffffea0001aa9640 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x100000000000100(slab) raw: 0100000000000100 0000000000000000 0000000000000000 0000000180800080 raw: ffffea0001abe380 0000000700000007 ffff88006c401b40 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88006aa59c80: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ffff88006aa59d00: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc >ffff88006aa59d80: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ^ ffff88006aa59e00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ffff88006aa59e80: fb fb fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ================================================================== from: ================================================================== BUG: KASAN: use-after-free in kmalloc_uaf+0xaa/0xb6 [test_kasan] at addr ffff88006c4dcb28 Write of size 1 by task insmod/3984 CPU: 1 PID: 3984 Comm: insmod Tainted: G B 4.10.0+ #83 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x292/0x398 kasan_object_err+0x1c/0x70 kasan_report.part.1+0x20e/0x4e0 __asan_report_store1_noabort+0x2c/0x30 kmalloc_uaf+0xaa/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x7feca0f779da RSP: 002b:00007ffdfeae5218 EFLAGS: 00000206 ORIG_RAX: 00000000000000af RAX: ffffffffffffffda RBX: 000055a064c13090 RCX: 00007feca0f779da RDX: 00007feca1236f88 RSI: 000000000004df7e RDI: 00007feca1605000 RBP: 00007feca1236f88 R08: 0000000000000003 R09: 0000000000000000 R10: 00007feca0f73d0a R11: 0000000000000206 R12: 000055a064c14190 R13: 000000000001fe81 R14: 0000000000000000 R15: 0000000000000004 Object at ffff88006c4dcb20, in cache kmalloc-16 size: 16 Allocated: PID = 3984 save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_kmalloc+0xad/0xe0 kmem_cache_alloc_trace+0x82/0x270 kmalloc_uaf+0x56/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 Freed: PID = 3984 save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_slab_free+0x73/0xc0 kfree+0xe8/0x2b0 kmalloc_uaf+0x85/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 Memory state around the buggy address: ffff88006c4dca00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ffff88006c4dca80: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc >ffff88006c4dcb00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ^ ffff88006c4dcb80: fb fb fc fc 00 00 fc fc fb fb fc fc fb fb fc fc ffff88006c4dcc00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ================================================================== This patch (of 9): Introduce get_shadow_bug_type() function, which determines bug type based on the shadow value for a particular kernel address. Introduce get_wild_bug_type() function, which determines bug type for addresses which don't have a corresponding shadow value. Link: http://lkml.kernel.org/r/20170302134851.101218-2-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Ingo Molnar
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58d30c36d4 |
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney: - Documentation updates. - Miscellaneous fixes. - Parallelize SRCU callback handling (plus overlapping patches). Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Paul E. McKenney
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5f0d5a3ae7 |
mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU
A group of Linux kernel hackers reported chasing a bug that resulted from their assumption that SLAB_DESTROY_BY_RCU provided an existence guarantee, that is, that no block from such a slab would be reallocated during an RCU read-side critical section. Of course, that is not the case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire slab of blocks. However, there is a phrase for this, namely "type safety". This commit therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order to avoid future instances of this sort of confusion. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <linux-mm@kvack.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> [ paulmck: Add comments mentioning the old name, as requested by Eric Dumazet, in order to help people familiar with the old name find the new one. ] Acked-by: David Rientjes <rientjes@google.com> |
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Mark Rutland
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b0845ce583 |
kasan: report only the first error by default
Disable kasan after the first report. There are several reasons for this: - Single bug quite often has multiple invalid memory accesses causing storm in the dmesg. - Write OOB access might corrupt metadata so the next report will print bogus alloc/free stacktraces. - Reports after the first easily could be not bugs by itself but just side effects of the first one. Given that multiple reports usually only do harm, it makes sense to disable kasan after the first one. If user wants to see all the reports, the boot-time parameter kasan_multi_shot must be used. [aryabinin@virtuozzo.com: wrote changelog and doc, added missing include] Link: http://lkml.kernel.org/r/20170323154416.30257-1-aryabinin@virtuozzo.com Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linus Torvalds
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baeedc7158 |
Merge branch 'prep-for-5level'
Merge 5-level page table prep from Kirill Shutemov: "Here's relatively low-risk part of 5-level paging patchset. Merging it now will make x86 5-level paging enabling in v4.12 easier. The first patch is actually x86-specific: detect 5-level paging support. It boils down to single define. The rest of patchset converts Linux MMU abstraction from 4- to 5-level paging. Enabling of new abstraction in most cases requires adding single line of code in arch-specific code. The rest is taken care by asm-generic/. Changes to mm/ code are mostly mechanical: add support for new page table level -- p4d_t -- where we deal with pud_t now. v2: - fix build on microblaze (Michal); - comment for __ARCH_HAS_5LEVEL_HACK in kasan_populate_zero_shadow(); - acks from Michal" * emailed patches from Kirill A Shutemov <kirill.shutemov@linux.intel.com>: mm: introduce __p4d_alloc() mm: convert generic code to 5-level paging asm-generic: introduce <asm-generic/pgtable-nop4d.h> arch, mm: convert all architectures to use 5level-fixup.h asm-generic: introduce __ARCH_USE_5LEVEL_HACK asm-generic: introduce 5level-fixup.h x86/cpufeature: Add 5-level paging detection |
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Dmitry Vyukov
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ce5bec54bb |
kasan: fix races in quarantine_remove_cache()
quarantine_remove_cache() frees all pending objects that belong to the cache, before we destroy the cache itself. However there are currently two possibilities how it can fail to do so. First, another thread can hold some of the objects from the cache in temp list in quarantine_put(). quarantine_put() has a windows of enabled interrupts, and on_each_cpu() in quarantine_remove_cache() can finish right in that window. These objects will be later freed into the destroyed cache. Then, quarantine_reduce() has the same problem. It grabs a batch of objects from the global quarantine, then unlocks quarantine_lock and then frees the batch. quarantine_remove_cache() can finish while some objects from the cache are still in the local to_free list in quarantine_reduce(). Fix the race with quarantine_put() by disabling interrupts for the whole duration of quarantine_put(). In combination with on_each_cpu() in quarantine_remove_cache() it ensures that quarantine_remove_cache() either sees the objects in the per-cpu list or in the global list. Fix the race with quarantine_reduce() by protecting quarantine_reduce() with srcu critical section and then doing synchronize_srcu() at the end of quarantine_remove_cache(). I've done some assessment of how good synchronize_srcu() works in this case. And on a 4 CPU VM I see that it blocks waiting for pending read critical sections in about 2-3% of cases. Which looks good to me. I suspect that these races are the root cause of some GPFs that I episodically hit. Previously I did not have any explanation for them. BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8 IP: qlist_free_all+0x2e/0xc0 mm/kasan/quarantine.c:155 PGD 6aeea067 PUD 60ed7067 PMD 0 Oops: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 13667 Comm: syz-executor2 Not tainted 4.10.0+ #60 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88005f948040 task.stack: ffff880069818000 RIP: 0010:qlist_free_all+0x2e/0xc0 mm/kasan/quarantine.c:155 RSP: 0018:ffff88006981f298 EFLAGS: 00010246 RAX: ffffea0000ffff00 RBX: 0000000000000000 RCX: ffffea0000ffff1f RDX: 0000000000000000 RSI: ffff88003fffc3e0 RDI: 0000000000000000 RBP: ffff88006981f2c0 R08: ffff88002fed7bd8 R09: 00000001001f000d R10: 00000000001f000d R11: ffff88006981f000 R12: ffff88003fffc3e0 R13: ffff88006981f2d0 R14: ffffffff81877fae R15: 0000000080000000 FS: 00007fb911a2d700(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000c8 CR3: 0000000060ed6000 CR4: 00000000000006f0 Call Trace: quarantine_reduce+0x10e/0x120 mm/kasan/quarantine.c:239 kasan_kmalloc+0xca/0xe0 mm/kasan/kasan.c:590 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544 slab_post_alloc_hook mm/slab.h:456 [inline] slab_alloc_node mm/slub.c:2718 [inline] kmem_cache_alloc_node+0x1d3/0x280 mm/slub.c:2754 __alloc_skb+0x10f/0x770 net/core/skbuff.c:219 alloc_skb include/linux/skbuff.h:932 [inline] _sctp_make_chunk+0x3b/0x260 net/sctp/sm_make_chunk.c:1388 sctp_make_data net/sctp/sm_make_chunk.c:1420 [inline] sctp_make_datafrag_empty+0x208/0x360 net/sctp/sm_make_chunk.c:746 sctp_datamsg_from_user+0x7e8/0x11d0 net/sctp/chunk.c:266 sctp_sendmsg+0x2611/0x3970 net/sctp/socket.c:1962 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x660/0x810 net/socket.c:1685 SyS_sendto+0x40/0x50 net/socket.c:1653 I am not sure about backporting. The bug is quite hard to trigger, I've seen it few times during our massive continuous testing (however, it could be cause of some other episodic stray crashes as it leads to memory corruption...). If it is triggered, the consequences are very bad -- almost definite bad memory corruption. The fix is non trivial and has chances of introducing new bugs. I am also not sure how actively people use KASAN on older releases. [dvyukov@google.com: - sorted includes[ Link: http://lkml.kernel.org/r/20170309094028.51088-1-dvyukov@google.com Link: http://lkml.kernel.org/r/20170308151532.5070-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Greg Thelen <gthelen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dmitry Vyukov
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68fd814a33 |
kasan: resched in quarantine_remove_cache()
We see reported stalls/lockups in quarantine_remove_cache() on machines with large amounts of RAM. quarantine_remove_cache() needs to scan whole quarantine in order to take out all objects belonging to the cache. Quarantine is currently 1/32-th of RAM, e.g. on a machine with 256GB of memory that will be 8GB. Moreover quarantine scanning is a walk over uncached linked list, which is slow. Add cond_resched() after scanning of each non-empty batch of objects. Batches are specifically kept of reasonable size for quarantine_put(). On a machine with 256GB of RAM we should have ~512 non-empty batches, each with 16MB of objects. Link: http://lkml.kernel.org/r/20170308154239.25440-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Greg Thelen <gthelen@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Kirill A. Shutemov
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c2febafc67 |
mm: convert generic code to 5-level paging
Convert all non-architecture-specific code to 5-level paging. It's mostly mechanical adding handling one more page table level in places where we deal with pud_t. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Ingo Molnar
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68db0cf106 |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar
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af8601ad42 |
kasan, sched/headers: Uninline kasan_enable/disable_current()
<linux/kasan.h> is a low level header that is included early in affected kernel headers. But it includes <linux/sched.h> which complicates the cleanup of sched.h dependencies. But kasan.h has almost no need for sched.h: its only use of scheduler functionality is in two inline functions which are not used very frequently - so uninline kasan_enable_current() and kasan_disable_current(). Also add a <linux/sched.h> dependency to a .c file that depended on kasan.h including it. This paves the way to remove the <linux/sched.h> include from kasan.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Greg Thelen
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f9fa1d919c |
kasan: drain quarantine of memcg slab objects
Per memcg slab accounting and kasan have a problem with kmem_cache
destruction.
- kmem_cache_create() allocates a kmem_cache, which is used for
allocations from processes running in root (top) memcg.
- Processes running in non root memcg and allocating with either
__GFP_ACCOUNT or from a SLAB_ACCOUNT cache use a per memcg
kmem_cache.
- Kasan catches use-after-free by having kfree() and kmem_cache_free()
defer freeing of objects. Objects are placed in a quarantine.
- kmem_cache_destroy() destroys root and non root kmem_caches. It takes
care to drain the quarantine of objects from the root memcg's
kmem_cache, but ignores objects associated with non root memcg. This
causes leaks because quarantined per memcg objects refer to per memcg
kmem cache being destroyed.
To see the problem:
1) create a slab cache with kmem_cache_create(,,,SLAB_ACCOUNT,)
2) from non root memcg, allocate and free a few objects from cache
3) dispose of the cache with kmem_cache_destroy() kmem_cache_destroy()
will trigger a "Slab cache still has objects" warning indicating
that the per memcg kmem_cache structure was leaked.
Fix the leak by draining kasan quarantined objects allocated from non
root memcg.
Racing memcg deletion is tricky, but handled. kmem_cache_destroy() =>
shutdown_memcg_caches() => __shutdown_memcg_cache() => shutdown_cache()
flushes per memcg quarantined objects, even if that memcg has been
rmdir'd and gone through memcg_deactivate_kmem_caches().
This leak only affects destroyed SLAB_ACCOUNT kmem caches when kasan is
enabled. So I don't think it's worth patching stable kernels.
Link: http://lkml.kernel.org/r/1482257462-36948-1-git-send-email-gthelen@google.com
Signed-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds
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ca78d3173c |
arm64 updates for 4.11:
- Errata workarounds for Qualcomm's Falkor CPU - Qualcomm L2 Cache PMU driver - Qualcomm SMCCC firmware quirk - Support for DEBUG_VIRTUAL - CPU feature detection for userspace via MRS emulation - Preliminary work for the Statistical Profiling Extension - Misc cleanups and non-critical fixes -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAABCgAGBQJYpIxqAAoJELescNyEwWM0xdwH/AsTYAXPZDMdRnrQUyV0Fd2H /9pMzww6dHXEmCMKkImf++otUD6S+gTCJTsj7kEAXT5sZzLk27std5lsW7R9oPjc bGQMalZy+ovLR1gJ6v072seM3In4xph/qAYOpD8Q0AfYCLHjfMMArQfoLa8Esgru eSsrAgzVAkrK7XHi3sYycUjr9Hac9tvOOuQ3SaZkDz4MfFIbI4b43+c1SCF7wgT9 tQUHLhhxzGmgxjViI2lLYZuBWsIWsE+algvOe1qocvA9JEIXF+W8NeOuCjdL8WwX 3aoqYClC+qD/9+/skShFv5gM5fo0/IweLTUNIHADXpB6OkCYDyg+sxNM+xnEWQU= =YrPg -----END PGP SIGNATURE----- Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: - Errata workarounds for Qualcomm's Falkor CPU - Qualcomm L2 Cache PMU driver - Qualcomm SMCCC firmware quirk - Support for DEBUG_VIRTUAL - CPU feature detection for userspace via MRS emulation - Preliminary work for the Statistical Profiling Extension - Misc cleanups and non-critical fixes * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (74 commits) arm64/kprobes: consistently handle MRS/MSR with XZR arm64: cpufeature: correctly handle MRS to XZR arm64: traps: correctly handle MRS/MSR with XZR arm64: ptrace: add XZR-safe regs accessors arm64: include asm/assembler.h in entry-ftrace.S arm64: fix warning about swapper_pg_dir overflow arm64: Work around Falkor erratum 1003 arm64: head.S: Enable EL1 (host) access to SPE when entered at EL2 arm64: arch_timer: document Hisilicon erratum 161010101 arm64: use is_vmalloc_addr arm64: use linux/sizes.h for constants arm64: uaccess: consistently check object sizes perf: add qcom l2 cache perf events driver arm64: remove wrong CONFIG_PROC_SYSCTL ifdef ARM: smccc: Update HVC comment to describe new quirk parameter arm64: do not trace atomic operations ACPI/IORT: Fix the error return code in iort_add_smmu_platform_device() ACPI/IORT: Fix iort_node_get_id() mapping entries indexing arm64: mm: enable CONFIG_HOLES_IN_ZONE for NUMA perf: xgene: Include module.h ... |
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Peter Zijlstra
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4f40c6e562 |
kasan: respect /proc/sys/kernel/traceoff_on_warning
After much waiting I finally reproduced a KASAN issue, only to find my trace-buffer empty of useful information because it got spooled out :/ Make kasan_report honour the /proc/sys/kernel/traceoff_on_warning interface. Link: http://lkml.kernel.org/r/20170125164106.3514-1-aryabinin@virtuozzo.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Laura Abbott
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5c6a84a3f4 |
mm/kasan: Switch to using __pa_symbol and lm_alias
__pa_symbol is the correct API to find the physical address of symbols. Switch to it to allow for debugging APIs to work correctly. Other functions such as p*d_populate may call __pa internally. Ensure that the address passed is in the linear region by calling lm_alias. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com> |
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Linus Torvalds
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7b9dc3f75f |
Power management material for v4.10-rc1
- New cpufreq driver for Broadcom STB SoCs and a Device Tree binding
for it (Markus Mayer).
- Support for ARM Integrator/AP and Integrator/CP in the generic
DT cpufreq driver and elimination of the old Integrator cpufreq
driver (Linus Walleij).
- Support for the zx296718, r8a7743 and r8a7745, Socionext UniPhier,
and PXA SoCs in the the generic DT cpufreq driver (Baoyou Xie,
Geert Uytterhoeven, Masahiro Yamada, Robert Jarzmik).
- cpufreq core fix to eliminate races that may lead to using
inactive policy objects and related cleanups (Rafael Wysocki).
- cpufreq schedutil governor update to make it use SCHED_FIFO
kernel threads (instead of regular workqueues) for doing delayed
work (to reduce the response latency in some cases) and related
cleanups (Viresh Kumar).
- New cpufreq sysfs attribute for resetting statistics (Markus
Mayer).
- cpufreq governors fixes and cleanups (Chen Yu, Stratos Karafotis,
Viresh Kumar).
- Support for using generic cpufreq governors in the intel_pstate
driver (Rafael Wysocki).
- Support for per-logical-CPU P-state limits and the EPP/EPB
(Energy Performance Preference/Energy Performance Bias) knobs
in the intel_pstate driver (Srinivas Pandruvada).
- New CPU ID for Knights Mill in intel_pstate (Piotr Luc).
- intel_pstate driver modification to use the P-state selection
algorithm based on CPU load on platforms with the system profile
in the ACPI tables set to "mobile" (Srinivas Pandruvada).
- intel_pstate driver cleanups (Arnd Bergmann, Rafael Wysocki,
Srinivas Pandruvada).
- cpufreq powernv driver updates including fast switching support
(for the schedutil governor), fixes and cleanus (Akshay Adiga,
Andrew Donnellan, Denis Kirjanov).
- acpi-cpufreq driver rework to switch it over to the new CPU
offline/online state machine (Sebastian Andrzej Siewior).
- Assorted cleanups in cpufreq drivers (Wei Yongjun, Prashanth
Prakash).
- Idle injection rework (to make it use the regular idle path
instead of a home-grown custom one) and related powerclamp
thermal driver updates (Peter Zijlstra, Jacob Pan, Petr Mladek,
Sebastian Andrzej Siewior).
- New CPU IDs for Atom Z34xx and Knights Mill in intel_idle (Andy
Shevchenko, Piotr Luc).
- intel_idle driver cleanups and switch over to using the new CPU
offline/online state machine (Anna-Maria Gleixner, Sebastian
Andrzej Siewior).
- cpuidle DT driver update to support suspend-to-idle properly
(Sudeep Holla).
- cpuidle core cleanups and misc updates (Daniel Lezcano, Pan Bian,
Rafael Wysocki).
- Preliminary support for power domains including CPUs in the
generic power domains (genpd) framework and related DT bindings
(Lina Iyer).
- Assorted fixes and cleanups in the generic power domains (genpd)
framework (Colin Ian King, Dan Carpenter, Geert Uytterhoeven).
- Preliminary support for devices with multiple voltage regulators
and related fixes and cleanups in the Operating Performance Points
(OPP) library (Viresh Kumar, Masahiro Yamada, Stephen Boyd).
- System sleep state selection interface rework to make it easier
to support suspend-to-idle as the default system suspend method
(Rafael Wysocki).
- PM core fixes and cleanups, mostly related to the interactions
between the system suspend and runtime PM frameworks (Ulf Hansson,
Sahitya Tummala, Tony Lindgren).
- Latency tolerance PM QoS framework imorovements (Andrew
Lutomirski).
- New Knights Mill CPU ID for the Intel RAPL power capping driver
(Piotr Luc).
- Intel RAPL power capping driver fixes, cleanups and switch over
to using the new CPU offline/online state machine (Jacob Pan,
Thomas Gleixner, Sebastian Andrzej Siewior).
- Fixes and cleanups in the exynos-ppmu, exynos-nocp, rk3399_dmc,
rockchip-dfi devfreq drivers and the devfreq core (Axel Lin,
Chanwoo Choi, Javier Martinez Canillas, MyungJoo Ham, Viresh
Kumar).
- Fix for false-positive KASAN warnings during resume from ACPI S3
(suspend-to-RAM) on x86 (Josh Poimboeuf).
- Memory map verification during resume from hibernation on x86 to
ensure a consistent address space layout (Chen Yu).
- Wakeup sources debugging enhancement (Xing Wei).
- rockchip-io AVS driver cleanup (Shawn Lin).
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Merge tag 'pm-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"Again, cpufreq gets more changes than the other parts this time (one
new driver, one old driver less, a bunch of enhancements of the
existing code, new CPU IDs, fixes, cleanups)
There also are some changes in cpuidle (idle injection rework, a
couple of new CPU IDs, online/offline rework in intel_idle, fixes and
cleanups), in the generic power domains framework (mostly related to
supporting power domains containing CPUs), and in the Operating
Performance Points (OPP) library (mostly related to supporting devices
with multiple voltage regulators)
In addition to that, the system sleep state selection interface is
modified to make it easier for distributions with unchanged user space
to support suspend-to-idle as the default system suspend method, some
issues are fixed in the PM core, the latency tolerance PM QoS
framework is improved a bit, the Intel RAPL power capping driver is
cleaned up and there are some fixes and cleanups in the devfreq
subsystem
Specifics:
- New cpufreq driver for Broadcom STB SoCs and a Device Tree binding
for it (Markus Mayer)
- Support for ARM Integrator/AP and Integrator/CP in the generic DT
cpufreq driver and elimination of the old Integrator cpufreq driver
(Linus Walleij)
- Support for the zx296718, r8a7743 and r8a7745, Socionext UniPhier,
and PXA SoCs in the the generic DT cpufreq driver (Baoyou Xie,
Geert Uytterhoeven, Masahiro Yamada, Robert Jarzmik)
- cpufreq core fix to eliminate races that may lead to using inactive
policy objects and related cleanups (Rafael Wysocki)
- cpufreq schedutil governor update to make it use SCHED_FIFO kernel
threads (instead of regular workqueues) for doing delayed work (to
reduce the response latency in some cases) and related cleanups
(Viresh Kumar)
- New cpufreq sysfs attribute for resetting statistics (Markus Mayer)
- cpufreq governors fixes and cleanups (Chen Yu, Stratos Karafotis,
Viresh Kumar)
- Support for using generic cpufreq governors in the intel_pstate
driver (Rafael Wysocki)
- Support for per-logical-CPU P-state limits and the EPP/EPB (Energy
Performance Preference/Energy Performance Bias) knobs in the
intel_pstate driver (Srinivas Pandruvada)
- New CPU ID for Knights Mill in intel_pstate (Piotr Luc)
- intel_pstate driver modification to use the P-state selection
algorithm based on CPU load on platforms with the system profile in
the ACPI tables set to "mobile" (Srinivas Pandruvada)
- intel_pstate driver cleanups (Arnd Bergmann, Rafael Wysocki,
Srinivas Pandruvada)
- cpufreq powernv driver updates including fast switching support
(for the schedutil governor), fixes and cleanus (Akshay Adiga,
Andrew Donnellan, Denis Kirjanov)
- acpi-cpufreq driver rework to switch it over to the new CPU
offline/online state machine (Sebastian Andrzej Siewior)
- Assorted cleanups in cpufreq drivers (Wei Yongjun, Prashanth
Prakash)
- Idle injection rework (to make it use the regular idle path instead
of a home-grown custom one) and related powerclamp thermal driver
updates (Peter Zijlstra, Jacob Pan, Petr Mladek, Sebastian Andrzej
Siewior)
- New CPU IDs for Atom Z34xx and Knights Mill in intel_idle (Andy
Shevchenko, Piotr Luc)
- intel_idle driver cleanups and switch over to using the new CPU
offline/online state machine (Anna-Maria Gleixner, Sebastian
Andrzej Siewior)
- cpuidle DT driver update to support suspend-to-idle properly
(Sudeep Holla)
- cpuidle core cleanups and misc updates (Daniel Lezcano, Pan Bian,
Rafael Wysocki)
- Preliminary support for power domains including CPUs in the generic
power domains (genpd) framework and related DT bindings (Lina Iyer)
- Assorted fixes and cleanups in the generic power domains (genpd)
framework (Colin Ian King, Dan Carpenter, Geert Uytterhoeven)
- Preliminary support for devices with multiple voltage regulators
and related fixes and cleanups in the Operating Performance Points
(OPP) library (Viresh Kumar, Masahiro Yamada, Stephen Boyd)
- System sleep state selection interface rework to make it easier to
support suspend-to-idle as the default system suspend method
(Rafael Wysocki)
- PM core fixes and cleanups, mostly related to the interactions
between the system suspend and runtime PM frameworks (Ulf Hansson,
Sahitya Tummala, Tony Lindgren)
- Latency tolerance PM QoS framework imorovements (Andrew Lutomirski)
- New Knights Mill CPU ID for the Intel RAPL power capping driver
(Piotr Luc)
- Intel RAPL power capping driver fixes, cleanups and switch over to
using the new CPU offline/online state machine (Jacob Pan, Thomas
Gleixner, Sebastian Andrzej Siewior)
- Fixes and cleanups in the exynos-ppmu, exynos-nocp, rk3399_dmc,
rockchip-dfi devfreq drivers and the devfreq core (Axel Lin,
Chanwoo Choi, Javier Martinez Canillas, MyungJoo Ham, Viresh Kumar)
- Fix for false-positive KASAN warnings during resume from ACPI S3
(suspend-to-RAM) on x86 (Josh Poimboeuf)
- Memory map verification during resume from hibernation on x86 to
ensure a consistent address space layout (Chen Yu)
- Wakeup sources debugging enhancement (Xing Wei)
- rockchip-io AVS driver cleanup (Shawn Lin)"
* tag 'pm-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (127 commits)
devfreq: rk3399_dmc: Don't use OPP structures outside of RCU locks
devfreq: rk3399_dmc: Remove dangling rcu_read_unlock()
devfreq: exynos: Don't use OPP structures outside of RCU locks
Documentation: intel_pstate: Document HWP energy/performance hints
cpufreq: intel_pstate: Support for energy performance hints with HWP
cpufreq: intel_pstate: Add locking around HWP requests
PM / sleep: Print active wakeup sources when blocking on wakeup_count reads
PM / core: Fix bug in the error handling of async suspend
PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspend
PM / Domains: Fix compatible for domain idle state
PM / OPP: Don't WARN on multiple calls to dev_pm_opp_set_regulators()
PM / OPP: Allow platform specific custom set_opp() callbacks
PM / OPP: Separate out _generic_set_opp()
PM / OPP: Add infrastructure to manage multiple regulators
PM / OPP: Pass struct dev_pm_opp_supply to _set_opp_voltage()
PM / OPP: Manage supply's voltage/current in a separate structure
PM / OPP: Don't use OPP structure outside of rcu protected section
PM / OPP: Reword binding supporting multiple regulators per device
PM / OPP: Fix incorrect cpu-supply property in binding
cpuidle: Add a kerneldoc comment to cpuidle_use_deepest_state()
..
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Dmitry Vyukov
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64abdcb243 |
kasan: eliminate long stalls during quarantine reduction
Currently we dedicate 1/32 of RAM for quarantine and then reduce it by 1/4 of total quarantine size. This can be a significant amount of memory. For example, with 4GB of RAM total quarantine size is 128MB and it is reduced by 32MB at a time. With 128GB of RAM total quarantine size is 4GB and it is reduced by 1GB. This leads to several problems: - freeing 1GB can take tens of seconds, causes rcu stall warnings and just introduces unexpected long delays at random places - if kmalloc() is called under a mutex, other threads stall on that mutex while a thread reduces quarantine - threads wait on quarantine_lock while one thread grabs a large batch of objects to evict - we walk the uncached list of object to free twice which makes all of the above worse - when a thread frees objects, they are already not accounted against global_quarantine.bytes; as the result we can have quarantine_size bytes in quarantine + unbounded amount of memory in large batches in threads that are in process of freeing Reduce size of quarantine in smaller batches to reduce the delays. The only reason to reduce it in batches is amortization of overheads, the new batch size of 1MB should be well enough to amortize spinlock lock/unlock and few function calls. Plus organize quarantine as a FIFO array of batches. This allows to not walk the list in quarantine_reduce() under quarantine_lock, which in turn reduces contention and is just faster. This improves performance of heavy load (syzkaller fuzzing) by ~20% with 4 CPUs and 32GB of RAM. Also this eliminates frequent (every 5 sec) drops of CPU consumption from ~400% to ~100% (one thread reduces quarantine while others are waiting on a mutex). Some reference numbers: 1. Machine with 4 CPUs and 4GB of memory. Quarantine size 128MB. Currently we free 32MB at at time. With new code we free 1MB at a time (1024 batches, ~128 are used). 2. Machine with 32 CPUs and 128GB of memory. Quarantine size 4GB. Currently we free 1GB at at time. With new code we free 8MB at a time (1024 batches, ~512 are used). 3. Machine with 4096 CPUs and 1TB of memory. Quarantine size 32GB. Currently we free 8GB at at time. With new code we free 4MB at a time (16K batches, ~8K are used). Link: http://lkml.kernel.org/r/1478756952-18695-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dmitry Vyukov
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5c5c1f36ce |
kasan: support panic_on_warn
If user sets panic_on_warn, he wants kernel to panic if there is anything barely wrong with the kernel. KASAN-detected errors are definitely not less benign than an arbitrary kernel WARNING. Panic after KASAN errors if panic_on_warn is set. We use this for continuous fuzzing where we want kernel to stop and reboot on any error. Link: http://lkml.kernel.org/r/1476694764-31986-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Rafael J. Wysocki
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631ddaba59 |
Merge branches 'pm-sleep' and 'powercap'
* pm-sleep: PM / sleep: Print active wakeup sources when blocking on wakeup_count reads x86/suspend: fix false positive KASAN warning on suspend/resume PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag PM / sleep: System sleep state selection interface rework PM / hibernate: Verify the consistent of e820 memory map by md5 digest * powercap: powercap / RAPL: Add Knights Mill CPUID powercap/intel_rapl: fix and tidy up error handling powercap/intel_rapl: Track active CPUs internally powercap/intel_rapl: Cleanup duplicated init code powercap/intel rapl: Convert to hotplug state machine powercap/intel_rapl: Propagate error code when registration fails powercap/intel_rapl: Add missing domain data update on hotplug |
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Josh Poimboeuf
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b53f40db59 |
x86/suspend: fix false positive KASAN warning on suspend/resume
Resuming from a suspend operation is showing a KASAN false positive warning: BUG: KASAN: stack-out-of-bounds in unwind_get_return_address+0x11d/0x130 at addr ffff8803867d7878 Read of size 8 by task pm-suspend/7774 page:ffffea000e19f5c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x2ffff0000000000() page dumped because: kasan: bad access detected CPU: 0 PID: 7774 Comm: pm-suspend Tainted: G B 4.9.0-rc7+ #8 Hardware name: Gigabyte Technology Co., Ltd. Z170X-UD5/Z170X-UD5-CF, BIOS F5 03/07/2016 Call Trace: dump_stack+0x63/0x82 kasan_report_error+0x4b4/0x4e0 ? acpi_hw_read_port+0xd0/0x1ea ? kfree_const+0x22/0x30 ? acpi_hw_validate_io_request+0x1a6/0x1a6 __asan_report_load8_noabort+0x61/0x70 ? unwind_get_return_address+0x11d/0x130 unwind_get_return_address+0x11d/0x130 ? unwind_next_frame+0x97/0xf0 __save_stack_trace+0x92/0x100 save_stack_trace+0x1b/0x20 save_stack+0x46/0xd0 ? save_stack_trace+0x1b/0x20 ? save_stack+0x46/0xd0 ? kasan_kmalloc+0xad/0xe0 ? kasan_slab_alloc+0x12/0x20 ? acpi_hw_read+0x2b6/0x3aa ? acpi_hw_validate_register+0x20b/0x20b ? acpi_hw_write_port+0x72/0xc7 ? acpi_hw_write+0x11f/0x15f ? acpi_hw_read_multiple+0x19f/0x19f ? memcpy+0x45/0x50 ? acpi_hw_write_port+0x72/0xc7 ? acpi_hw_write+0x11f/0x15f ? acpi_hw_read_multiple+0x19f/0x19f ? kasan_unpoison_shadow+0x36/0x50 kasan_kmalloc+0xad/0xe0 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc_trace+0xbc/0x1e0 ? acpi_get_sleep_type_data+0x9a/0x578 acpi_get_sleep_type_data+0x9a/0x578 acpi_hw_legacy_wake_prep+0x88/0x22c ? acpi_hw_legacy_sleep+0x3c7/0x3c7 ? acpi_write_bit_register+0x28d/0x2d3 ? acpi_read_bit_register+0x19b/0x19b acpi_hw_sleep_dispatch+0xb5/0xba acpi_leave_sleep_state_prep+0x17/0x19 acpi_suspend_enter+0x154/0x1e0 ? trace_suspend_resume+0xe8/0xe8 suspend_devices_and_enter+0xb09/0xdb0 ? printk+0xa8/0xd8 ? arch_suspend_enable_irqs+0x20/0x20 ? try_to_freeze_tasks+0x295/0x600 pm_suspend+0x6c9/0x780 ? finish_wait+0x1f0/0x1f0 ? suspend_devices_and_enter+0xdb0/0xdb0 state_store+0xa2/0x120 ? kobj_attr_show+0x60/0x60 kobj_attr_store+0x36/0x70 sysfs_kf_write+0x131/0x200 kernfs_fop_write+0x295/0x3f0 __vfs_write+0xef/0x760 ? handle_mm_fault+0x1346/0x35e0 ? do_iter_readv_writev+0x660/0x660 ? __pmd_alloc+0x310/0x310 ? do_lock_file_wait+0x1e0/0x1e0 ? apparmor_file_permission+0x18/0x20 ? security_file_permission+0x73/0x1c0 ? rw_verify_area+0xbd/0x2b0 vfs_write+0x149/0x4a0 SyS_write+0xd9/0x1c0 ? SyS_read+0x1c0/0x1c0 entry_SYSCALL_64_fastpath+0x1e/0xad Memory state around the buggy address: ffff8803867d7700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8803867d7780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8803867d7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f4 ^ ffff8803867d7880: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 ffff8803867d7900: 00 00 00 f1 f1 f1 f1 04 f4 f4 f4 f3 f3 f3 f3 00 KASAN instrumentation poisons the stack when entering a function and unpoisons it when exiting the function. However, in the suspend path, some functions never return, so their stack never gets unpoisoned, resulting in stale KASAN shadow data which can cause later false positive warnings like the one above. Reported-by: Scott Bauer <scott.bauer@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
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Dmitry Vyukov
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828347f8f9 |
kasan: support use-after-scope detection
Gcc revision 241896 implements use-after-scope detection. Will be available in gcc 7. Support it in KASAN. Gcc emits 2 new callbacks to poison/unpoison large stack objects when they go in/out of scope. Implement the callbacks and add a test. [dvyukov@google.com: v3] Link: http://lkml.kernel.org/r/1479998292-144502-1-git-send-email-dvyukov@google.com Link: http://lkml.kernel.org/r/1479226045-145148-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dmitry Vyukov
|
045d599a28 |
kasan: update kasan_global for gcc 7
kasan_global struct is part of compiler/runtime ABI. gcc revision 241983 has added a new field to kasan_global struct. Update kernel definition of kasan_global struct to include the new field. Without this patch KASAN is broken with gcc 7. Link: http://lkml.kernel.org/r/1479219743-28682-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dmitry Vyukov
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9f7d416c36 |
kprobes: Unpoison stack in jprobe_return() for KASAN
I observed false KSAN positives in the sctp code, when sctp uses jprobe_return() in jsctp_sf_eat_sack(). The stray 0xf4 in shadow memory are stack redzones: [ ] ================================================================== [ ] BUG: KASAN: stack-out-of-bounds in memcmp+0xe9/0x150 at addr ffff88005e48f480 [ ] Read of size 1 by task syz-executor/18535 [ ] page:ffffea00017923c0 count:0 mapcount:0 mapping: (null) index:0x0 [ ] flags: 0x1fffc0000000000() [ ] page dumped because: kasan: bad access detected [ ] CPU: 1 PID: 18535 Comm: syz-executor Not tainted 4.8.0+ #28 [ ] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ ] ffff88005e48f2d0 ffffffff82d2b849 ffffffff0bc91e90 fffffbfff10971e8 [ ] ffffed000bc91e90 ffffed000bc91e90 0000000000000001 0000000000000000 [ ] ffff88005e48f480 ffff88005e48f350 ffffffff817d3169 ffff88005e48f370 [ ] Call Trace: [ ] [<ffffffff82d2b849>] dump_stack+0x12e/0x185 [ ] [<ffffffff817d3169>] kasan_report+0x489/0x4b0 [ ] [<ffffffff817d31a9>] __asan_report_load1_noabort+0x19/0x20 [ ] [<ffffffff82d49529>] memcmp+0xe9/0x150 [ ] [<ffffffff82df7486>] depot_save_stack+0x176/0x5c0 [ ] [<ffffffff817d2031>] save_stack+0xb1/0xd0 [ ] [<ffffffff817d27f2>] kasan_slab_free+0x72/0xc0 [ ] [<ffffffff817d05b8>] kfree+0xc8/0x2a0 [ ] [<ffffffff85b03f19>] skb_free_head+0x79/0xb0 [ ] [<ffffffff85b0900a>] skb_release_data+0x37a/0x420 [ ] [<ffffffff85b090ff>] skb_release_all+0x4f/0x60 [ ] [<ffffffff85b11348>] consume_skb+0x138/0x370 [ ] [<ffffffff8676ad7b>] sctp_chunk_put+0xcb/0x180 [ ] [<ffffffff8676ae88>] sctp_chunk_free+0x58/0x70 [ ] [<ffffffff8677fa5f>] sctp_inq_pop+0x68f/0xef0 [ ] [<ffffffff8675ee36>] sctp_assoc_bh_rcv+0xd6/0x4b0 [ ] [<ffffffff8677f2c1>] sctp_inq_push+0x131/0x190 [ ] [<ffffffff867bad69>] sctp_backlog_rcv+0xe9/0xa20 [ ... ] [ ] Memory state around the buggy address: [ ] ffff88005e48f380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] ffff88005e48f400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] >ffff88005e48f480: f4 f4 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] ^ [ ] ffff88005e48f500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] ffff88005e48f580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] ================================================================== KASAN stack instrumentation poisons stack redzones on function entry and unpoisons them on function exit. If a function exits abnormally (e.g. with a longjmp like jprobe_return()), stack redzones are left poisoned. Later this leads to random KASAN false reports. Unpoison stack redzones in the frames we are going to jump over before doing actual longjmp in jprobe_return(). Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: kasan-dev@googlegroups.com Cc: surovegin@google.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/1476454043-101898-1-git-send-email-dvyukov@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Alexander Potapenko
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bcbf0d566b |
kasan: remove the unnecessary WARN_ONCE from quarantine.c
It's quite unlikely that the user will so little memory that the per-CPU quarantines won't fit into the given fraction of the available memory. Even in that case he won't be able to do anything with the information given in the warning. Link: http://lkml.kernel.org/r/1470929182-101413-1-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Potapenko
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c3cee37228 |
kasan: avoid overflowing quarantine size on low memory systems
If the total amount of memory assigned to quarantine is less than the
amount of memory assigned to per-cpu quarantines, |new_quarantine_size|
may overflow. Instead, set it to zero.
[akpm@linux-foundation.org: cleanup: use WARN_ONCE return value]
Link: http://lkml.kernel.org/r/1470063563-96266-1-git-send-email-glider@google.com
Fixes:
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Andrey Ryabinin
|
7e08897893 |
kasan: improve double-free reports
Currently we just dump stack in case of double free bug. Let's dump all info about the object that we have. [aryabinin@virtuozzo.com: change double free message per Alexander] Link: http://lkml.kernel.org/r/1470153654-30160-1-git-send-email-aryabinin@virtuozzo.com Link: http://lkml.kernel.org/r/1470062715-14077-6-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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b3cbd9bf77 |
mm/kasan: get rid of ->state in struct kasan_alloc_meta
The state of object currently tracked in two places - shadow memory, and the ->state field in struct kasan_alloc_meta. We can get rid of the latter. The will save us a little bit of memory. Also, this allow us to move free stack into struct kasan_alloc_meta, without increasing memory consumption. So now we should always know when the last time the object was freed. This may be useful for long delayed use-after-free bugs. As a side effect this fixes following UBSAN warning: UBSAN: Undefined behaviour in mm/kasan/quarantine.c:102:13 member access within misaligned address ffff88000d1efebc for type 'struct qlist_node' which requires 8 byte alignment Link: http://lkml.kernel.org/r/1470062715-14077-5-git-send-email-aryabinin@virtuozzo.com Reported-by: kernel test robot <xiaolong.ye@intel.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
|
47b5c2a0f0 |
mm/kasan: get rid of ->alloc_size in struct kasan_alloc_meta
Size of slab object already stored in cache->object_size. Note, that kmalloc() internally rounds up size of allocation, so object_size may be not equal to alloc_size, but, usually we don't need to know the exact size of allocated object. In case if we need that information, we still can figure it out from the report. The dump of shadow memory allows to identify the end of allocated memory, and thereby the exact allocation size. Link: http://lkml.kernel.org/r/1470062715-14077-4-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
|
f7376aed6c |
mm/kasan, slub: don't disable interrupts when object leaves quarantine
SLUB doesn't require disabled interrupts to call ___cache_free(). Link: http://lkml.kernel.org/r/1470062715-14077-3-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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4b3ec5a3f4 |
mm/kasan: don't reduce quarantine in atomic contexts
Currently we call quarantine_reduce() for ___GFP_KSWAPD_RECLAIM (implied
by __GFP_RECLAIM) allocation. So, basically we call it on almost every
allocation. quarantine_reduce() sometimes is heavy operation, and
calling it with disabled interrupts may trigger hard LOCKUP:
NMI watchdog: Watchdog detected hard LOCKUP on cpu 2irq event stamp: 1411258
Call Trace:
<NMI> dump_stack+0x68/0x96
watchdog_overflow_callback+0x15b/0x190
__perf_event_overflow+0x1b1/0x540
perf_event_overflow+0x14/0x20
intel_pmu_handle_irq+0x36a/0xad0
perf_event_nmi_handler+0x2c/0x50
nmi_handle+0x128/0x480
default_do_nmi+0xb2/0x210
do_nmi+0x1aa/0x220
end_repeat_nmi+0x1a/0x1e
<<EOE>> __kernel_text_address+0x86/0xb0
print_context_stack+0x7b/0x100
dump_trace+0x12b/0x350
save_stack_trace+0x2b/0x50
set_track+0x83/0x140
free_debug_processing+0x1aa/0x420
__slab_free+0x1d6/0x2e0
___cache_free+0xb6/0xd0
qlist_free_all+0x83/0x100
quarantine_reduce+0x177/0x1b0
kasan_kmalloc+0xf3/0x100
Reduce the quarantine_reduce iff direct reclaim is allowed.
Fixes: 55834c59098d("mm: kasan: initial memory quarantine implementation")
Link: http://lkml.kernel.org/r/1470062715-14077-2-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andrey Ryabinin
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4a3d308d66 |
mm/kasan: fix corruptions and false positive reports
Once an object is put into quarantine, we no longer own it, i.e. object
could leave the quarantine and be reallocated. So having set_track()
call after the quarantine_put() may corrupt slab objects.
BUG kmalloc-4096 (Not tainted): Poison overwritten
-----------------------------------------------------------------------------
Disabling lock debugging due to kernel taint
INFO: 0xffff8804540de850-0xffff8804540de857. First byte 0xb5 instead of 0x6b
...
INFO: Freed in qlist_free_all+0x42/0x100 age=75 cpu=3 pid=24492
__slab_free+0x1d6/0x2e0
___cache_free+0xb6/0xd0
qlist_free_all+0x83/0x100
quarantine_reduce+0x177/0x1b0
kasan_kmalloc+0xf3/0x100
kasan_slab_alloc+0x12/0x20
kmem_cache_alloc+0x109/0x3e0
mmap_region+0x53e/0xe40
do_mmap+0x70f/0xa50
vm_mmap_pgoff+0x147/0x1b0
SyS_mmap_pgoff+0x2c7/0x5b0
SyS_mmap+0x1b/0x30
do_syscall_64+0x1a0/0x4e0
return_from_SYSCALL_64+0x0/0x7a
INFO: Slab 0xffffea0011503600 objects=7 used=7 fp=0x (null) flags=0x8000000000004080
INFO: Object 0xffff8804540de848 @offset=26696 fp=0xffff8804540dc588
Redzone ffff8804540de840: bb bb bb bb bb bb bb bb ........
Object ffff8804540de848: 6b 6b 6b 6b 6b 6b 6b 6b b5 52 00 00 f2 01 60 cc kkkkkkkk.R....`.
Similarly, poisoning after the quarantine_put() leads to false positive
use-after-free reports:
BUG: KASAN: use-after-free in anon_vma_interval_tree_insert+0x304/0x430 at addr ffff880405c540a0
Read of size 8 by task trinity-c0/3036
CPU: 0 PID: 3036 Comm: trinity-c0 Not tainted 4.7.0-think+ #9
Call Trace:
dump_stack+0x68/0x96
kasan_report_error+0x222/0x600
__asan_report_load8_noabort+0x61/0x70
anon_vma_interval_tree_insert+0x304/0x430
anon_vma_chain_link+0x91/0xd0
anon_vma_clone+0x136/0x3f0
anon_vma_fork+0x81/0x4c0
copy_process.part.47+0x2c43/0x5b20
_do_fork+0x16d/0xbd0
SyS_clone+0x19/0x20
do_syscall_64+0x1a0/0x4e0
entry_SYSCALL64_slow_path+0x25/0x25
Fix this by putting an object in the quarantine after all other
operations.
Fixes:
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Alexander Potapenko
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80a9201a59 |
mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB
For KASAN builds: - switch SLUB allocator to using stackdepot instead of storing the allocation/deallocation stacks in the objects; - change the freelist hook so that parts of the freelist can be put into the quarantine. [aryabinin@virtuozzo.com: fixes] Link: http://lkml.kernel.org/r/1468601423-28676-1-git-send-email-aryabinin@virtuozzo.com Link: http://lkml.kernel.org/r/1468347165-41906-3-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Joonsoo Kim
|
0ab686d8c8 |
kasan/quarantine: fix bugs on qlist_move_cache()
There are two bugs on qlist_move_cache(). One is that qlist's tail
isn't set properly. curr->next can be NULL since it is singly linked
list and NULL value on tail is invalid if there is one item on qlist.
Another one is that if cache is matched, qlist_put() is called and it
will set curr->next to NULL. It would cause to stop the loop
prematurely.
These problems come from complicated implementation so I'd like to
re-implement it completely. Implementation in this patch is really
simple. Iterate all qlist_nodes and put them to appropriate list.
Unfortunately, I got this bug sometime ago and lose oops message. But,
the bug looks trivial and no need to attach oops.
Fixes:
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Andrey Ryabinin
|
9b75a867cc |
mm: mempool: kasan: don't poot mempool objects in quarantine
Currently we may put reserved by mempool elements into quarantine via
kasan_kfree(). This is totally wrong since quarantine may really free
these objects. So when mempool will try to use such element,
use-after-free will happen. Or mempool may decide that it no longer
need that element and double-free it.
So don't put object into quarantine in kasan_kfree(), just poison it.
Rename kasan_kfree() to kasan_poison_kfree() to respect that.
Also, we shouldn't use kasan_slab_alloc()/kasan_krealloc() in
kasan_unpoison_element() because those functions may update allocation
stacktrace. This would be wrong for the most of the remove_element call
sites.
(The only call site where we may want to update alloc stacktrace is
in mempool_alloc(). Kmemleak solves this by calling
kmemleak_update_trace(), so we could make something like that too.
But this is out of scope of this patch).
Fixes:
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Shuah Khan
|
91a4c27214 |
kasan: change memory hot-add error messages to info messages
Change the following memory hot-add error messages to info messages. There is no need for these to be errors. kasan: WARNING: KASAN doesn't support memory hot-add kasan: Memory hot-add will be disabled Link: http://lkml.kernel.org/r/1464794430-5486-1-git-send-email-shuahkh@osg.samsung.com Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
|
9725759a96 |
mm: kasan: remove unused 'reserved' field from struct kasan_alloc_meta
Commit
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Andrey Ryabinin
|
64f8ebaf11 |
mm/kasan: add API to check memory regions
Memory access coded in an assembly won't be seen by KASAN as a compiler can instrument only C code. Add kasan_check_[read,write]() API which is going to be used to check a certain memory range. Link: http://lkml.kernel.org/r/1462538722-1574-3-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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936bb4bbbb |
mm/kasan: print name of mem[set,cpy,move]() caller in report
When bogus memory access happens in mem[set,cpy,move]() it's usually caller's fault. So don't blame mem[set,cpy,move]() in bug report, blame the caller instead. Before: BUG: KASAN: out-of-bounds access in memset+0x23/0x40 at <address> After: BUG: KASAN: out-of-bounds access in <memset_caller> at <address> Link: http://lkml.kernel.org/r/1462538722-1574-2-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Potapenko
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55834c5909 |
mm: kasan: initial memory quarantine implementation
Quarantine isolates freed objects in a separate queue. The objects are returned to the allocator later, which helps to detect use-after-free errors. When the object is freed, its state changes from KASAN_STATE_ALLOC to KASAN_STATE_QUARANTINE. The object is poisoned and put into quarantine instead of being returned to the allocator, therefore every subsequent access to that object triggers a KASAN error, and the error handler is able to say where the object has been allocated and deallocated. When it's time for the object to leave quarantine, its state becomes KASAN_STATE_FREE and it's returned to the allocator. From now on the allocator may reuse it for another allocation. Before that happens, it's still possible to detect a use-after free on that object (it retains the allocation/deallocation stacks). When the allocator reuses this object, the shadow is unpoisoned and old allocation/deallocation stacks are wiped. Therefore a use of this object, even an incorrect one, won't trigger ASan warning. Without the quarantine, it's not guaranteed that the objects aren't reused immediately, that's why the probability of catching a use-after-free is lower than with quarantine in place. Quarantine isolates freed objects in a separate queue. The objects are returned to the allocator later, which helps to detect use-after-free errors. Freed objects are first added to per-cpu quarantine queues. When a cache is destroyed or memory shrinking is requested, the objects are moved into the global quarantine queue. Whenever a kmalloc call allows memory reclaiming, the oldest objects are popped out of the global queue until the total size of objects in quarantine is less than 3/4 of the maximum quarantine size (which is a fraction of installed physical memory). As long as an object remains in the quarantine, KASAN is able to report accesses to it, so the chance of reporting a use-after-free is increased. Once the object leaves quarantine, the allocator may reuse it, in which case the object is unpoisoned and KASAN can't detect incorrect accesses to it. Right now quarantine support is only enabled in SLAB allocator. Unification of KASAN features in SLAB and SLUB will be done later. This patch is based on the "mm: kasan: quarantine" patch originally prepared by Dmitry Chernenkov. A number of improvements have been suggested by Andrey Ryabinin. [glider@google.com: v9] Link: http://lkml.kernel.org/r/1462987130-144092-1-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Potapenko
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0b355eaaaa |
mm, kasan: fix compilation for CONFIG_SLAB
Add the missing argument to set_track().
Fixes:
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Alexander Potapenko
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cd11016e5f |
mm, kasan: stackdepot implementation. Enable stackdepot for SLAB
Implement the stack depot and provide CONFIG_STACKDEPOT. Stack depot will allow KASAN store allocation/deallocation stack traces for memory chunks. The stack traces are stored in a hash table and referenced by handles which reside in the kasan_alloc_meta and kasan_free_meta structures in the allocated memory chunks. IRQ stack traces are cut below the IRQ entry point to avoid unnecessary duplication. Right now stackdepot support is only enabled in SLAB allocator. Once KASAN features in SLAB are on par with those in SLUB we can switch SLUB to stackdepot as well, thus removing the dependency on SLUB stack bookkeeping, which wastes a lot of memory. This patch is based on the "mm: kasan: stack depots" patch originally prepared by Dmitry Chernenkov. Joonsoo has said that he plans to reuse the stackdepot code for the mm/page_owner.c debugging facility. [akpm@linux-foundation.org: s/depot_stack_handle/depot_stack_handle_t] [aryabinin@virtuozzo.com: comment style fixes] Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Potapenko
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505f5dcb1c |
mm, kasan: add GFP flags to KASAN API
Add GFP flags to KASAN hooks for future patches to use. This patch is based on the "mm: kasan: unified support for SLUB and SLAB allocators" patch originally prepared by Dmitry Chernenkov. Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Potapenko
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7ed2f9e663 |
mm, kasan: SLAB support
Add KASAN hooks to SLAB allocator. This patch is based on the "mm: kasan: unified support for SLUB and SLAB allocators" patch originally prepared by Dmitry Chernenkov. Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dmitry Vyukov
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5c9a8750a6 |
kernel: add kcov code coverage
kcov provides code coverage collection for coverage-guided fuzzing (randomized testing). Coverage-guided fuzzing is a testing technique that uses coverage feedback to determine new interesting inputs to a system. A notable user-space example is AFL (http://lcamtuf.coredump.cx/afl/). However, this technique is not widely used for kernel testing due to missing compiler and kernel support. kcov does not aim to collect as much coverage as possible. It aims to collect more or less stable coverage that is function of syscall inputs. To achieve this goal it does not collect coverage in soft/hard interrupts and instrumentation of some inherently non-deterministic or non-interesting parts of kernel is disbled (e.g. scheduler, locking). Currently there is a single coverage collection mode (tracing), but the API anticipates additional collection modes. Initially I also implemented a second mode which exposes coverage in a fixed-size hash table of counters (what Quentin used in his original patch). I've dropped the second mode for simplicity. This patch adds the necessary support on kernel side. The complimentary compiler support was added in gcc revision 231296. We've used this support to build syzkaller system call fuzzer, which has found 90 kernel bugs in just 2 months: https://github.com/google/syzkaller/wiki/Found-Bugs We've also found 30+ bugs in our internal systems with syzkaller. Another (yet unexplored) direction where kcov coverage would greatly help is more traditional "blob mutation". For example, mounting a random blob as a filesystem, or receiving a random blob over wire. Why not gcov. Typical fuzzing loop looks as follows: (1) reset coverage, (2) execute a bit of code, (3) collect coverage, repeat. A typical coverage can be just a dozen of basic blocks (e.g. an invalid input). In such context gcov becomes prohibitively expensive as reset/collect coverage steps depend on total number of basic blocks/edges in program (in case of kernel it is about 2M). Cost of kcov depends only on number of executed basic blocks/edges. On top of that, kernel requires per-thread coverage because there are always background threads and unrelated processes that also produce coverage. With inlined gcov instrumentation per-thread coverage is not possible. kcov exposes kernel PCs and control flow to user-space which is insecure. But debugfs should not be mapped as user accessible. Based on a patch by Quentin Casasnovas. [akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode'] [akpm@linux-foundation.org: unbreak allmodconfig] [akpm@linux-foundation.org: follow x86 Makefile layout standards] Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: syzkaller <syzkaller@googlegroups.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Tavis Ormandy <taviso@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@google.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: David Drysdale <drysdale@google.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Joe Perches
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756a025f00 |
mm: coalesce split strings
Kernel style prefers a single string over split strings when the string is 'user-visible'. Miscellanea: - Add a missing newline - Realign arguments Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Tejun Heo <tj@kernel.org> [percpu] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mark Rutland
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e3ae116339 |
kasan: add functions to clear stack poison
Functions which the compiler has instrumented for ASAN place poison on the stack shadow upon entry and remove this poison prior to returning. In some cases (e.g. hotplug and idle), CPUs may exit the kernel a number of levels deep in C code. If there are any instrumented functions on this critical path, these will leave portions of the idle thread stack shadow poisoned. If a CPU returns to the kernel via a different path (e.g. a cold entry), then depending on stack frame layout subsequent calls to instrumented functions may use regions of the stack with stale poison, resulting in (spurious) KASAN splats to the console. Contemporary GCCs always add stack shadow poisoning when ASAN is enabled, even when asked to not instrument a function [1], so we can't simply annotate functions on the critical path to avoid poisoning. Instead, this series explicitly removes any stale poison before it can be hit. In the common hotplug case we clear the entire stack shadow in common code, before a CPU is brought online. On architectures which perform a cold return as part of cpu idle may retain an architecture-specific amount of stack contents. To retain the poison for this retained context, the arch code must call the core KASAN code, passing a "watermark" stack pointer value beyond which shadow will be cleared. Architectures which don't perform a cold return as part of idle do not need any additional code. This patch (of 3): Functions which the compiler has instrumented for KASAN place poison on the stack shadow upon entry and remove this poision prior to returning. In some cases (e.g. hotplug and idle), CPUs may exit the kernel a number of levels deep in C code. If there are any instrumented functions on this critical path, these will leave portions of the stack shadow poisoned. If a CPU returns to the kernel via a different path (e.g. a cold entry), then depending on stack frame layout subsequent calls to instrumented functions may use regions of the stack with stale poison, resulting in (spurious) KASAN splats to the console. To avoid this, we must clear stale poison from the stack prior to instrumented functions being called. This patch adds functions to the KASAN core for removing poison from (portions of) a task's stack. These will be used by subsequent patches to avoid problems with hotplug and idle. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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c6d308534a |
UBSAN: run-time undefined behavior sanity checker
UBSAN uses compile-time instrumentation to catch undefined behavior (UB). Compiler inserts code that perform certain kinds of checks before operations that could cause UB. If check fails (i.e. UB detected) __ubsan_handle_* function called to print error message. So the most of the work is done by compiler. This patch just implements ubsan handlers printing errors. GCC has this capability since 4.9.x [1] (see -fsanitize=undefined option and its suboptions). However GCC 5.x has more checkers implemented [2]. Article [3] has a bit more details about UBSAN in the GCC. [1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html [2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html [3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/ Issues which UBSAN has found thus far are: Found bugs: * out-of-bounds access - |
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Andrey Ryabinin
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459372545c |
kasan: fix kmemleak false-positive in kasan_module_alloc()
Kmemleak reports the following leak: unreferenced object 0xfffffbfff41ea000 (size 20480): comm "modprobe", pid 65199, jiffies 4298875551 (age 542.568s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff82354f5e>] kmemleak_alloc+0x4e/0xc0 [<ffffffff8152e718>] __vmalloc_node_range+0x4b8/0x740 [<ffffffff81574072>] kasan_module_alloc+0x72/0xc0 [<ffffffff810efe68>] module_alloc+0x78/0xb0 [<ffffffff812f6a24>] module_alloc_update_bounds+0x14/0x70 [<ffffffff812f8184>] layout_and_allocate+0x16f4/0x3c90 [<ffffffff812faa1f>] load_module+0x2ff/0x6690 [<ffffffff813010b6>] SyS_finit_module+0x136/0x170 [<ffffffff8239bbc9>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff kasan_module_alloc() allocates shadow memory for module and frees it on module unloading. It doesn't store the pointer to allocated shadow memory because it could be calculated from the shadowed address, i.e. kasan_mem_to_shadow(addr). Since kmemleak cannot find pointer to allocated shadow, it thinks that memory leaked. Use kmemleak_ignore() to tell kmemleak that this is not a leak and shadow memory doesn't contain any pointers. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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eb06f43f1c |
kasan: always taint kernel on report
Currently we already taint the kernel in some cases. E.g. if we hit some bug in slub memory we call object_err() which will taint the kernel with TAINT_BAD_PAGE flag. But for other kind of bugs kernel left untainted. Always taint with TAINT_BAD_PAGE if kasan found some bug. This is useful for automated testing. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Xishi Qiu
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10f702627e |
kasan: use IS_ALIGNED in memory_is_poisoned_8()
Use IS_ALIGNED() to determine whether the shadow span two bytes. It generates less code and more readable. Also add some comments in shadow check functions. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Wang Long
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e0d5771439 |
kasan: Fix a type conversion error
The current KASAN code can not find the following out-of-bounds bugs:
char *ptr;
ptr = kmalloc(8, GFP_KERNEL);
memset(ptr+7, 0, 2);
the cause of the problem is the type conversion error in
*memory_is_poisoned_n* function. So this patch fix that.
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andrey Konovalov
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5d0926efe7 |
kasan: update reference to kasan prototype repo
Update the reference to the kasan prototype repository on github, since it was renamed. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konstantin Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Konovalov
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25add7ec70 |
kasan: update log messages
We decided to use KASAN as the short name of the tool and KernelAddressSanitizer as the full one. Update log messages according to that. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konstantin Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Konovalov
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cdf6a273dc |
kasan: accurately determine the type of the bad access
Makes KASAN accurately determine the type of the bad access. If the shadow byte value is in the [0, KASAN_SHADOW_SCALE_SIZE) range we can look at the next shadow byte to determine the type of the access. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konstantin Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Konovalov
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0952d87fd6 |
kasan: update reported bug types for kernel memory accesses
Update the names of the bad access types to better reflect the type of the access that happended and make these error types "literals" that can be used for classification and deduplication in scripts. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konstantin Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Konovalov
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e912107663 |
kasan: update reported bug types for not user nor kernel memory accesses
Each access with address lower than kasan_shadow_to_mem(KASAN_SHADOW_START) is reported as user-memory-access. This is not always true, the accessed address might not be in user space. Fix this by reporting such accesses as null-ptr-derefs or wild-memory-accesses. There's another reason for this change. For userspace ASan we have a bunch of systems that analyze error types for the purpose of classification and deduplication. Sooner of later we will write them to KASAN as well. Then clearly and explicitly stated error types will bring value. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konstantin Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Aneesh Kumar K.V
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fc5aeeaf59 |
mm/kasan: prevent deadlock in kasan reporting
When we end up calling kasan_report in real mode, our shadow mapping for the spinlock variable will show poisoned. This will result in us calling kasan_report_error with lock_report spin lock held. To prevent this disable kasan reporting when we are priting error w.r.t kasan. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Aneesh Kumar K.V
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f2377d4eaa |
mm/kasan: don't use kasan shadow pointer in generic functions
We can't use generic functions like print_hex_dump to access kasan shadow region. This require us to setup another kasan shadow region for the address passed (kasan shadow address). Some architectures won't be able to do that. Hence make a copy of the shadow region row and pass that to generic functions. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Aneesh Kumar K.V
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527f215b78 |
mm/kasan: MODULE_VADDR is not available on all archs
Use is_module_address instead Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Aneesh Kumar K.V
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0ba8663cbf |
mm/kasan: rename kasan_enabled() to kasan_report_enabled()
The function only disable/enable reporting. In the later patch we will be adding a kasan early enable/disable. Rename kasan_enabled to properly reflect its function. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Xishi Qiu
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8d77a6d18a |
kasan: fix last shadow judgement in memory_is_poisoned_16()
The shadow which correspond 16 bytes memory may span 2 or 3 bytes. If the memory is aligned on 8, then the shadow takes only 2 bytes. So we check "shadow_first_bytes" is enough, and need not to call "memory_is_poisoned_1(addr + 15);". But the code "if (likely(!last_byte))" is wrong judgement. e.g. addr=0, so last_byte = 15 & KASAN_SHADOW_MASK = 7, then the code will continue to call "memory_is_poisoned_1(addr + 15);" Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Michal Marek <mmarek@suse.cz> Cc: <zhongjiang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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69786cdb37 |
x86/kasan, mm: Introduce generic kasan_populate_zero_shadow()
Introduce generic kasan_populate_zero_shadow(shadow_start, shadow_end). This function maps kasan_zero_page to the [shadow_start, shadow_end] addresses. This replaces x86_64 specific populate_zero_shadow() and will be used for ARM64 in follow on patches. The main changes from original version are: * Use p?d_populate*() instead of set_p?d() * Use memblock allocator directly instead of vmemmap_alloc_block() * __pa() instead of __pa_nodebug(). __pa() causes troubles iff we use it before kasan_early_init(). kasan_populate_zero_shadow() will be used later, so we ok with __pa() here. Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexey Klimov <klimov.linux@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Keitel <dkeitel@codeaurora.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Yury <yury.norov@gmail.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1439444244-26057-3-git-send-email-ryabinin.a.a@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Andrey Ryabinin
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2baf9e8948 |
.mailmap: Andrey Ryabinin has moved
Update my email address. Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Wang Long
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bffacb9132 |
kasan: remove duplicate definition of the macro KASAN_FREE_PAGE
Remove duplicate definition of the macro KASAN_FREE_PAGE in mm/kasan/kasan.h Signed-off-by: Wang Long <long.wanglong@huawei.com> Acked-by: Andrey Ryabinin <a.ryabinin@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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923936157b |
mm/mempool.c: kasan: poison mempool elements
Mempools keep allocated objects in reserved for situations when ordinary allocation may not be possible to satisfy. These objects shouldn't be accessed before they leave the pool. This patch poison elements when get into the pool and unpoison when they leave it. This will let KASan to detect use-after-free of mempool's elements. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Tested-by: David Rientjes <rientjes@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Chernenkov <drcheren@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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a5af5aa8b6 |
kasan, module, vmalloc: rework shadow allocation for modules
Current approach in handling shadow memory for modules is broken.
Shadow memory could be freed only after memory shadow corresponds it is no
longer used. vfree() called from interrupt context could use memory its
freeing to store 'struct llist_node' in it:
void vfree(const void *addr)
{
...
if (unlikely(in_interrupt())) {
struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred);
if (llist_add((struct llist_node *)addr, &p->list))
schedule_work(&p->wq);
Later this list node used in free_work() which actually frees memory.
Currently module_memfree() called in interrupt context will free shadow
before freeing module's memory which could provoke kernel crash.
So shadow memory should be freed after module's memory. However, such
deallocation order could race with kasan_module_alloc() in module_alloc().
Free shadow right before releasing vm area. At this point vfree()'d
memory is not used anymore and yet not available for other allocations.
New VM_KASAN flag used to indicate that vm area has dynamically allocated
shadow memory so kasan frees shadow only if it was previously allocated.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andrey Ryabinin
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bebf56a1b1 |
kasan: enable instrumentation of global variables
This feature let us to detect accesses out of bounds of global variables. This will work as for globals in kernel image, so for globals in modules. Currently this won't work for symbols in user-specified sections (e.g. __init, __read_mostly, ...) The idea of this is simple. Compiler increases each global variable by redzone size and add constructors invoking __asan_register_globals() function. Information about global variable (address, size, size with redzone ...) passed to __asan_register_globals() so we could poison variable's redzone. This patch also forces module_alloc() to return 8*PAGE_SIZE aligned address making shadow memory handling ( kasan_module_alloc()/kasan_module_free() ) more simple. Such alignment guarantees that each shadow page backing modules address space correspond to only one module_alloc() allocation. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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c420f167db |
kasan: enable stack instrumentation
Stack instrumentation allows to detect out of bounds memory accesses for variables allocated on stack. Compiler adds redzones around every variable on stack and poisons redzones in function's prologue. Such approach significantly increases stack usage, so all in-kernel stacks size were doubled. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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393f203f5f |
x86_64: kasan: add interceptors for memset/memmove/memcpy functions
Recently instrumentation of builtin functions calls was removed from GCC 5.0. To check the memory accessed by such functions, userspace asan always uses interceptors for them. So now we should do this as well. This patch declares memset/memmove/memcpy as weak symbols. In mm/kasan/kasan.c we have our own implementation of those functions which checks memory before accessing it. Default memset/memmove/memcpy now now always have aliases with '__' prefix. For files that built without kasan instrumentation (e.g. mm/slub.c) original mem* replaced (via #define) with prefixed variants, cause we don't want to check memory accesses there. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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0316bec22e |
mm: slub: add kernel address sanitizer support for slub allocator
With this patch kasan will be able to catch bugs in memory allocated by slub. Initially all objects in newly allocated slab page, marked as redzone. Later, when allocation of slub object happens, requested by caller number of bytes marked as accessible, and the rest of the object (including slub's metadata) marked as redzone (inaccessible). We also mark object as accessible if ksize was called for this object. There is some places in kernel where ksize function is called to inquire size of really allocated area. Such callers could validly access whole allocated memory, so it should be marked as accessible. Code in slub.c and slab_common.c files could validly access to object's metadata, so instrumentation for this files are disabled. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Signed-off-by: Dmitry Chernenkov <dmitryc@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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b8c73fc249 |
mm: page_alloc: add kasan hooks on alloc and free paths
Add kernel address sanitizer hooks to mark allocated page's addresses as accessible in corresponding shadow region. Mark freed pages as inaccessible. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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786a895991 |
kasan: disable memory hotplug
Currently memory hotplug won't work with KASan. As we don't have shadow for hotplugged memory, kernel will crash on the first access to it. To make this work we will need to allocate shadow for new memory. At some future point proper memory hotplug support will be implemented. Until then, print a warning at startup and disable memory hot-add. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrey Ryabinin
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0b24becc81 |
kasan: add kernel address sanitizer infrastructure
Kernel Address sanitizer (KASan) is a dynamic memory error detector. It
provides fast and comprehensive solution for finding use-after-free and
out-of-bounds bugs.
KASAN uses compile-time instrumentation for checking every memory access,
therefore GCC > v4.9.2 required. v4.9.2 almost works, but has issues with
putting symbol aliases into the wrong section, which breaks kasan
instrumentation of globals.
This patch only adds infrastructure for kernel address sanitizer. It's
not available for use yet. The idea and some code was borrowed from [1].
Basic idea:
The main idea of KASAN is to use shadow memory to record whether each byte
of memory is safe to access or not, and use compiler's instrumentation to
check the shadow memory on each memory access.
Address sanitizer uses 1/8 of the memory addressable in kernel for shadow
memory and uses direct mapping with a scale and offset to translate a
memory address to its corresponding shadow address.
Here is function to translate address to corresponding shadow address:
unsigned long kasan_mem_to_shadow(unsigned long addr)
{
return (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET;
}
where KASAN_SHADOW_SCALE_SHIFT = 3.
So for every 8 bytes there is one corresponding byte of shadow memory.
The following encoding used for each shadow byte: 0 means that all 8 bytes
of the corresponding memory region are valid for access; k (1 <= k <= 7)
means that the first k bytes are valid for access, and other (8 - k) bytes
are not; Any negative value indicates that the entire 8-bytes are
inaccessible. Different negative values used to distinguish between
different kinds of inaccessible memory (redzones, freed memory) (see
mm/kasan/kasan.h).
To be able to detect accesses to bad memory we need a special compiler.
Such compiler inserts a specific function calls (__asan_load*(addr),
__asan_store*(addr)) before each memory access of size 1, 2, 4, 8 or 16.
These functions check whether memory region is valid to access or not by
checking corresponding shadow memory. If access is not valid an error
printed.
Historical background of the address sanitizer from Dmitry Vyukov:
"We've developed the set of tools, AddressSanitizer (Asan),
ThreadSanitizer and MemorySanitizer, for user space. We actively use
them for testing inside of Google (continuous testing, fuzzing,
running prod services). To date the tools have found more than 10'000
scary bugs in Chromium, Google internal codebase and various
open-source projects (Firefox, OpenSSL, gcc, clang, ffmpeg, MySQL and
lots of others): [2] [3] [4].
The tools are part of both gcc and clang compilers.
We have not yet done massive testing under the Kernel AddressSanitizer
(it's kind of chicken and egg problem, you need it to be upstream to
start applying it extensively). To date it has found about 50 bugs.
Bugs that we've found in upstream kernel are listed in [5].
We've also found ~20 bugs in out internal version of the kernel. Also
people from Samsung and Oracle have found some.
[...]
As others noted, the main feature of AddressSanitizer is its
performance due to inline compiler instrumentation and simple linear
shadow memory. User-space Asan has ~2x slowdown on computational
programs and ~2x memory consumption increase. Taking into account that
kernel usually consumes only small fraction of CPU and memory when
running real user-space programs, I would expect that kernel Asan will
have ~10-30% slowdown and similar memory consumption increase (when we
finish all tuning).
I agree that Asan can well replace kmemcheck. We have plans to start
working on Kernel MemorySanitizer that finds uses of unitialized
memory. Asan+Msan will provide feature-parity with kmemcheck. As
others noted, Asan will unlikely replace debug slab and pagealloc that
can be enabled at runtime. Asan uses compiler instrumentation, so even
if it is disabled, it still incurs visible overheads.
Asan technology is easily portable to other architectures. Compiler
instrumentation is fully portable. Runtime has some arch-dependent
parts like shadow mapping and atomic operation interception. They are
relatively easy to port."
Comparison with other debugging features:
========================================
KMEMCHECK:
- KASan can do almost everything that kmemcheck can. KASan uses
compile-time instrumentation, which makes it significantly faster than
kmemcheck. The only advantage of kmemcheck over KASan is detection of
uninitialized memory reads.
Some brief performance testing showed that kasan could be
x500-x600 times faster than kmemcheck:
$ netperf -l 30
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost (127.0.0.1) port 0 AF_INET
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
no debug: 87380 16384 16384 30.00 41624.72
kasan inline: 87380 16384 16384 30.00 12870.54
kasan outline: 87380 16384 16384 30.00 10586.39
kmemcheck: 87380 16384 16384 30.03 20.23
- Also kmemcheck couldn't work on several CPUs. It always sets
number of CPUs to 1. KASan doesn't have such limitation.
DEBUG_PAGEALLOC:
- KASan is slower than DEBUG_PAGEALLOC, but KASan works on sub-page
granularity level, so it able to find more bugs.
SLUB_DEBUG (poisoning, redzones):
- SLUB_DEBUG has lower overhead than KASan.
- SLUB_DEBUG in most cases are not able to detect bad reads,
KASan able to detect both reads and writes.
- In some cases (e.g. redzone overwritten) SLUB_DEBUG detect
bugs only on allocation/freeing of object. KASan catch
bugs right before it will happen, so we always know exact
place of first bad read/write.
[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel
[2] https://code.google.com/p/address-sanitizer/wiki/FoundBugs
[3] https://code.google.com/p/thread-sanitizer/wiki/FoundBugs
[4] https://code.google.com/p/memory-sanitizer/wiki/FoundBugs
[5] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel#Trophies
Based on work by Andrey Konovalov.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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