linux_dsm_epyc7002/drivers/target
Shin'ichiro Kawasaki e65d6887fc scsi: target: tcmu: Fix use-after-free of se_cmd->priv
commit 780e1384687d6ecdee9ca789a1027610484ac8a2 upstream.

Commit a35129024e ("scsi: target: tcmu: Use priv pointer in se_cmd")
modified tcmu_free_cmd() to set NULL to priv pointer in se_cmd. However,
se_cmd can be already freed by work queue triggered in
target_complete_cmd(). This caused BUG KASAN use-after-free [1].

To fix the bug, do not touch priv pointer in tcmu_free_cmd(). Instead, set
NULL to priv pointer before target_complete_cmd() calls. Also, to avoid
unnecessary priv pointer change in tcmu_queue_cmd(), modify priv pointer in
the function only when tcmu_free_cmd() is not called.

[1]
BUG: KASAN: use-after-free in tcmu_handle_completions+0x1172/0x1770 [target_core_user]
Write of size 8 at addr ffff88814cf79a40 by task cmdproc-uio0/14842

CPU: 2 PID: 14842 Comm: cmdproc-uio0 Not tainted 5.11.0-rc2 #1
Hardware name: Supermicro Super Server/X10SRL-F, BIOS 3.2 11/22/2019
Call Trace:
 dump_stack+0x9a/0xcc
 ? tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 print_address_description.constprop.0+0x18/0x130
 ? tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 ? tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 kasan_report.cold+0x7f/0x10e
 ? tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 tcmu_handle_completions+0x1172/0x1770 [target_core_user]
 ? queue_tmr_ring+0x5d0/0x5d0 [target_core_user]
 tcmu_irqcontrol+0x28/0x60 [target_core_user]
 uio_write+0x155/0x230
 ? uio_vma_fault+0x460/0x460
 ? security_file_permission+0x4f/0x440
 vfs_write+0x1ce/0x860
 ksys_write+0xe9/0x1b0
 ? __ia32_sys_read+0xb0/0xb0
 ? syscall_enter_from_user_mode+0x27/0x70
 ? trace_hardirqs_on+0x1c/0x110
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fcf8b61905f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 b9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 0c fd ff ff 48
RSP: 002b:00007fcf7b3e6c30 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf8b61905f
RDX: 0000000000000004 RSI: 00007fcf7b3e6c78 RDI: 000000000000000c
RBP: 00007fcf7b3e6c80 R08: 0000000000000000 R09: 00007fcf7b3e6aa8
R10: 000000000b01c000 R11: 0000000000000293 R12: 00007ffe0c32a52e
R13: 00007ffe0c32a52f R14: 0000000000000000 R15: 00007fcf7b3e7640

Allocated by task 383:
 kasan_save_stack+0x1b/0x40
 ____kasan_kmalloc.constprop.0+0x84/0xa0
 kmem_cache_alloc+0x142/0x330
 tcm_loop_queuecommand+0x2a/0x4e0 [tcm_loop]
 scsi_queue_rq+0x12ec/0x2d20
 blk_mq_dispatch_rq_list+0x30a/0x1db0
 __blk_mq_do_dispatch_sched+0x326/0x830
 __blk_mq_sched_dispatch_requests+0x2c8/0x3f0
 blk_mq_sched_dispatch_requests+0xca/0x120
 __blk_mq_run_hw_queue+0x93/0xe0
 process_one_work+0x7b6/0x1290
 worker_thread+0x590/0xf80
 kthread+0x362/0x430
 ret_from_fork+0x22/0x30

Freed by task 11655:
 kasan_save_stack+0x1b/0x40
 kasan_set_track+0x1c/0x30
 kasan_set_free_info+0x20/0x30
 ____kasan_slab_free+0xec/0x120
 slab_free_freelist_hook+0x53/0x160
 kmem_cache_free+0xf4/0x5c0
 target_release_cmd_kref+0x3ea/0x9e0 [target_core_mod]
 transport_generic_free_cmd+0x28b/0x2f0 [target_core_mod]
 target_complete_ok_work+0x250/0xac0 [target_core_mod]
 process_one_work+0x7b6/0x1290
 worker_thread+0x590/0xf80
 kthread+0x362/0x430
 ret_from_fork+0x22/0x30

Last potentially related work creation:
 kasan_save_stack+0x1b/0x40
 kasan_record_aux_stack+0xa3/0xb0
 insert_work+0x48/0x2e0
 __queue_work+0x4e8/0xdf0
 queue_work_on+0x78/0x80
 tcmu_handle_completions+0xad0/0x1770 [target_core_user]
 tcmu_irqcontrol+0x28/0x60 [target_core_user]
 uio_write+0x155/0x230
 vfs_write+0x1ce/0x860
 ksys_write+0xe9/0x1b0
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Second to last potentially related work creation:
 kasan_save_stack+0x1b/0x40
 kasan_record_aux_stack+0xa3/0xb0
 insert_work+0x48/0x2e0
 __queue_work+0x4e8/0xdf0
 queue_work_on+0x78/0x80
 tcm_loop_queuecommand+0x1c3/0x4e0 [tcm_loop]
 scsi_queue_rq+0x12ec/0x2d20
 blk_mq_dispatch_rq_list+0x30a/0x1db0
 __blk_mq_do_dispatch_sched+0x326/0x830
 __blk_mq_sched_dispatch_requests+0x2c8/0x3f0
 blk_mq_sched_dispatch_requests+0xca/0x120
 __blk_mq_run_hw_queue+0x93/0xe0
 process_one_work+0x7b6/0x1290
 worker_thread+0x590/0xf80
 kthread+0x362/0x430
 ret_from_fork+0x22/0x30

The buggy address belongs to the object at ffff88814cf79800 which belongs
to the cache tcm_loop_cmd_cache of size 896.

Link: https://lore.kernel.org/r/20210113024508.1264992-1-shinichiro.kawasaki@wdc.com
Fixes: a35129024e ("scsi: target: tcmu: Use priv pointer in se_cmd")
Cc: stable@vger.kernel.org # v5.9+
Acked-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:54:50 +01:00
..
iscsi scsi: target: iscsi: Fix cmd abort fabric stop race 2020-11-16 23:34:18 -05:00
loopback scsi: target: loopback: Fix READ with data and sensebytes 2020-05-11 22:20:19 -04:00
sbp treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
tcm_fc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile
target_core_alua.c scsi: target: Make transport_flags per device 2020-05-07 22:39:21 -04:00
target_core_alua.h
target_core_configfs.c scsi: target: tcmu: Make pgr_support and alua_support attributes writable 2020-05-07 22:39:22 -04:00
target_core_device.c scsi: target: Initialize LUN in transport_init_se_cmd() 2020-06-09 21:57:26 -04:00
target_core_fabric_configfs.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
target_core_fabric_lib.c scsi: target: Handle short iSIDs 2020-07-08 00:14:34 -04:00
target_core_file.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
target_core_file.h
target_core_hba.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
target_core_iblock.c target/iblock: fix holder printing in iblock_show_configfs_dev_params 2020-09-25 08:18:58 -06:00
target_core_iblock.h
target_core_internal.h scsi: target: Fix xcopy sess release leak 2020-07-08 00:14:34 -04:00
target_core_pr.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
target_core_pr.h scsi: target/core: Rework the SPC-2 reservation handling code 2019-04-12 20:20:05 -04:00
target_core_pscsi.c scsi: target: Make transport_flags per device 2020-05-07 22:39:21 -04:00
target_core_pscsi.h
target_core_rd.c scsi: target: rd: Drop double zeroing 2020-10-07 23:50:03 -04:00
target_core_rd.h
target_core_sbc.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
target_core_spc.c scsi: target: use an enum to track emulate_ua_intlck_ctrl 2020-02-21 17:37:16 -05:00
target_core_stat.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
target_core_tmr.c scsi: target: Add tmr_notify backend function 2020-07-28 22:25:26 -04:00
target_core_tpg.c scsi: target: Make transport_flags per device 2020-05-07 22:39:21 -04:00
target_core_transport.c SCSI fixes on 20201002 2020-10-02 14:42:13 -07:00
target_core_ua.c scsi: target: use an enum to track emulate_ua_intlck_ctrl 2020-02-21 17:37:16 -05:00
target_core_ua.h
target_core_user.c scsi: target: tcmu: Fix use-after-free of se_cmd->priv 2021-01-27 11:54:50 +01:00
target_core_xcopy.c scsi: target: Fix XCOPY NAA identifier lookup 2021-01-12 20:18:27 +01:00
target_core_xcopy.h scsi: target: Fix XCOPY NAA identifier lookup 2021-01-12 20:18:27 +01:00