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Bart Van Assche e9d3009cb9 scsi: target: iscsi: Wait for all commands to finish before freeing a session
The iSCSI target driver is the only target driver that does not wait for
ongoing commands to finish before freeing a session. Make the iSCSI target
driver wait for ongoing commands to finish before freeing a session. This
patch fixes the following KASAN complaint:

BUG: KASAN: use-after-free in __lock_acquire+0xb1a/0x2710
Read of size 8 at addr ffff8881154eca70 by task kworker/0:2/247

CPU: 0 PID: 247 Comm: kworker/0:2 Not tainted 5.4.0-rc1-dbg+ #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Workqueue: target_completion target_complete_ok_work [target_core_mod]
Call Trace:
 dump_stack+0x8a/0xd6
 print_address_description.constprop.0+0x40/0x60
 __kasan_report.cold+0x1b/0x33
 kasan_report+0x16/0x20
 __asan_load8+0x58/0x90
 __lock_acquire+0xb1a/0x2710
 lock_acquire+0xd3/0x200
 _raw_spin_lock_irqsave+0x43/0x60
 target_release_cmd_kref+0x162/0x7f0 [target_core_mod]
 target_put_sess_cmd+0x2e/0x40 [target_core_mod]
 lio_check_stop_free+0x12/0x20 [iscsi_target_mod]
 transport_cmd_check_stop_to_fabric+0xd8/0xe0 [target_core_mod]
 target_complete_ok_work+0x1b0/0x790 [target_core_mod]
 process_one_work+0x549/0xa40
 worker_thread+0x7a/0x5d0
 kthread+0x1bc/0x210
 ret_from_fork+0x24/0x30

Allocated by task 889:
 save_stack+0x23/0x90
 __kasan_kmalloc.constprop.0+0xcf/0xe0
 kasan_slab_alloc+0x12/0x20
 kmem_cache_alloc+0xf6/0x360
 transport_alloc_session+0x29/0x80 [target_core_mod]
 iscsi_target_login_thread+0xcd6/0x18f0 [iscsi_target_mod]
 kthread+0x1bc/0x210
 ret_from_fork+0x24/0x30

Freed by task 1025:
 save_stack+0x23/0x90
 __kasan_slab_free+0x13a/0x190
 kasan_slab_free+0x12/0x20
 kmem_cache_free+0x146/0x400
 transport_free_session+0x179/0x2f0 [target_core_mod]
 transport_deregister_session+0x130/0x180 [target_core_mod]
 iscsit_close_session+0x12c/0x350 [iscsi_target_mod]
 iscsit_logout_post_handler+0x136/0x380 [iscsi_target_mod]
 iscsit_response_queue+0x8de/0xbe0 [iscsi_target_mod]
 iscsi_target_tx_thread+0x27f/0x370 [iscsi_target_mod]
 kthread+0x1bc/0x210
 ret_from_fork+0x24/0x30

The buggy address belongs to the object at ffff8881154ec9c0
 which belongs to the cache se_sess_cache of size 352
The buggy address is located 176 bytes inside of
 352-byte region [ffff8881154ec9c0, ffff8881154ecb20)
The buggy address belongs to the page:
page:ffffea0004553b00 refcount:1 mapcount:0 mapping:ffff888101755400 index:0x0 compound_mapcount: 0
flags: 0x2fff000000010200(slab|head)
raw: 2fff000000010200 dead000000000100 dead000000000122 ffff888101755400
raw: 0000000000000000 0000000080130013 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881154ec900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881154ec980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8881154eca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8881154eca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881154ecb00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc

Cc: Mike Christie <mchristi@redhat.com>
Link: https://lore.kernel.org/r/20191113220508.198257-3-bvanassche@acm.org
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-11-19 21:37:35 -05:00
Documentation scsi: core: Clean up SG_NONE 2019-11-12 22:21:35 -05:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch csky-for-linus-5.4-rc1: arch/csky patches for 5.4-rc1 2019-09-30 10:16:17 -07:00
block block: fix null pointer dereference in blk_mq_rq_timed_out() 2019-09-27 07:01:25 -06:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
drivers scsi: target: iscsi: Wait for all commands to finish before freeing a session 2019-11-19 21:37:35 -05:00
fs for-5.4-rc1-tag 2019-09-30 10:25:24 -07:00
include scsi: target: iscsi: Wait for all commands to finish before freeing a session 2019-11-19 21:37:35 -05:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel A few more tracing fixes: 2019-09-30 09:29:53 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-28 17:47:33 -07:00
mm Merge branch 'hugepage-fallbacks' (hugepatch patches from David Rientjes) 2019-09-28 14:26:47 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-28 17:47:33 -07:00
samples rpmsg updates for v5.4 2019-09-22 10:58:15 -07:00
scripts Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2019-09-27 19:37:27 -07:00
security Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
sound sound fixes for 5.4-rc1 2019-09-24 16:46:16 -07:00
tools A few more tracing fixes: 2019-09-30 09:29:53 -07:00
usr Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-28 17:47:33 -07:00
virt * s390: ioctl hardening, selftests 2019-09-18 09:49:13 -07:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-09-18 12:34:53 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS CREDITS: Update email address 2019-09-13 17:21:38 +03:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge branch '5.4/scsi-fixes' into 5.5/scsi-queue 2019-10-09 21:54:04 -04:00
Makefile Linux 5.4-rc1 2019-09-30 10:35:40 -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.