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Rafael J. Wysocki 1a1c130ab7 ACPI: tables: x86: Reserve memory occupied by ACPI tables
The following problem has been reported by George Kennedy:

 Since commit 7fef431be9 ("mm/page_alloc: place pages to tail
 in __free_pages_core()") the following use after free occurs
 intermittently when ACPI tables are accessed.

 BUG: KASAN: use-after-free in ibft_init+0x134/0xc49
 Read of size 4 at addr ffff8880be453004 by task swapper/0/1
 CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc1-7a7fd0d #1
 Call Trace:
  dump_stack+0xf6/0x158
  print_address_description.constprop.9+0x41/0x60
  kasan_report.cold.14+0x7b/0xd4
  __asan_report_load_n_noabort+0xf/0x20
  ibft_init+0x134/0xc49
  do_one_initcall+0xc4/0x3e0
  kernel_init_freeable+0x5af/0x66b
  kernel_init+0x16/0x1d0
  ret_from_fork+0x22/0x30

 ACPI tables mapped via kmap() do not have their mapped pages
 reserved and the pages can be "stolen" by the buddy allocator.

Apparently, on the affected system, the ACPI table in question is
not located in "reserved" memory, like ACPI NVS or ACPI Data, that
will not be used by the buddy allocator, so the memory occupied by
that table has to be explicitly reserved to prevent the buddy
allocator from using it.

In order to address this problem, rearrange the initialization of the
ACPI tables on x86 to locate the initial tables earlier and reserve
the memory occupied by them.

The other architectures using ACPI should not be affected by this
change.

Link: https://lore.kernel.org/linux-acpi/1614802160-29362-1-git-send-email-george.kennedy@oracle.com/
Reported-by: George Kennedy <george.kennedy@oracle.com>
Tested-by: George Kennedy <george.kennedy@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
2021-03-29 19:26:04 +02:00
Documentation arm64 fixes for -rc5 2021-03-25 11:07:40 -07:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
arch ACPI: tables: x86: Reserve memory occupied by ACPI tables 2021-03-29 19:26:04 +02:00
block block: don't create too many partitions 2021-03-27 09:22:18 -06:00
certs certs: Replace K{U,G}IDT_INIT() with GLOBAL_ROOT_{U,G}ID 2021-01-21 16:16:10 +00:00
crypto crypto: mips/poly1305 - enable for all MIPS processors 2021-03-08 11:52:17 +01:00
drivers ACPI: tables: x86: Reserve memory occupied by ACPI tables 2021-03-29 19:26:04 +02:00
fs 5 cifs/smb3 fixes, 2 for stable, includes an important fix for encryption and an ACL fix, as well as a fix for possible reflink data corruption 2021-03-28 12:06:21 -07:00
include ACPI: tables: x86: Reserve memory occupied by ACPI tables 2021-03-29 19:26:04 +02:00
init Merge branch 'akpm' (patches from Andrew) 2021-03-14 12:23:34 -07:00
ipc fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
kernel io_uring-5.12-2021-03-27 2021-03-28 11:42:05 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-03-24 18:16:04 -07:00
mm Merge branch 'akpm' (patches from Andrew) 2021-03-25 11:43:43 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-03-24 18:16:04 -07:00
samples Merge git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2021-03-09 17:15:56 -08:00
scripts kbuild: fix ld-version.sh to not be affected by locale 2021-03-13 11:12:13 +09:00
security integrity-v5.12-fix 2021-03-25 16:46:43 -07:00
sound sound fixes for 5.12-rc4 2021-03-19 09:53:32 -07:00
tools Some more perf tools fixes for v5.12: 2021-03-28 13:22:54 -07:00
usr Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
virt KVM: x86/mmu: Consider the hva in mmu_notifier retry 2021-02-22 13:16:53 -05:00
.clang-format cxl for 5.12 2021-02-24 09:38:36 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore clang-lto series for v5.12-rc1 2021-02-23 09:28:51 -08:00
.mailmap Merge branch 'akpm' (patches from Andrew) 2021-03-25 11:43:43 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS treewide: Miguel has moved 2021-02-26 09:41:03 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ARM: SoC fixes for v5.12 2021-03-26 11:19:38 -07:00
Makefile Linux 5.12-rc5 2021-03-28 15:48:16 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.