dm: fix NULL pointer dereference in __dm_suspend()
In the Linux kernel, the following vulnerability has been resolved:
dm: fix NULL pointer dereference in __dm_suspend()
There is a race condition between dm device suspend and table load that
can lead to null pointer dereference. The issue occurs when suspend is
invoked before table load completes:
BUG: kernel NULL pointer dereference, address: 0000000000000054
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 6 PID: 6798 Comm: dmsetup Not tainted 6.6.0-g7e52f5f0ca9b #62
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014
RIP: 0010:blk_mq_wait_quiesce_done+0x0/0x50
Call Trace:
blk_mq_quiesce_queue+0x2c/0x50
dm_stop_queue+0xd/0x20
__dm_suspend+0x130/0x330
dm_suspend+0x11a/0x180
dev_suspend+0x27e/0x560
ctl_ioctl+0x4cf/0x850
dm_ctl_ioctl+0xd/0x20
vfs_ioctl+0x1d/0x50
__se_sys_ioctl+0x9b/0xc0
__x64_sys_ioctl+0x19/0x30
x64_sys_call+0x2c4a/0x4620
do_syscall_64+0x9e/0x1b0
The issue can be triggered as below:
T1 T2
dm_suspend table_load
__dm_suspend dm_setup_md_queue
dm_mq_init_request_queue
blk_mq_init_allocated_queue
=> q->mq_ops = set->ops; (1)
dm_stop_queue / dm_wait_for_completion
=> q->tag_set NULL pointer! (2)
=> q->tag_set = set; (3)
Fix this by checking if a valid table (map) exists before performing
request-based suspend and waiting for target I/O. When map is NULL,
skip these table-dependent suspend steps.
Even when map is NULL, no I/O can reach any target because there is
no table loaded; I/O submitted in this state will fail early in the
DM layer. Skipping the table-dependent suspend logic in this case
is safe and avoids NULL pointer dereferences.
CVE 정보
EPSS
EPSS는 취약점이 악용될 가능성을 예측하는 점수 모델입니다.
EPSS 점수
EPSS 모델은 0과 1(0~100%) 사이의 확률 점수를 생성합니다. 점수가 높을수록 취약점이 악용될 가능성이 높습니다.
날짜
EPSS V0
EPSS V1
EPSS V2 (> 2022-02-04)
EPSS V3 (> 2025-03-07)
EPSS V4 (> 2025-03-17)
2025-11-12
–
–
–
–
0.02%
2025-11-15
–
–
–
–
0.02%
2025-11-18
–
–
–
–
0.03%
2025-11-21
–
–
–
–
0.03%
2025-11-28
–
–
–
–
0.03%
2025-11-29
–
–
–
–
0.03%
2025-12-14
–
–
–
–
0.04%
2025-12-18
–
–
–
–
0.06%
2026-01-05
–
–
–
–
0.05%
2026-01-19
–
–
–
–
0.05%
2026-03-01
–
–
–
–
0.05%
2026-03-15
–
–
–
–
0.07%
2026-04-12
–
–
–
–
0.04%
2026-04-26
–
–
–
–
0.06%
2026-06-14
–
–
–
–
0.07%
EPSS 백분위수
백분위수는 EPSS 점수에 따라 CVE의 순위를 매기는 데 사용됩니다. 예를 들어 EPSS 점수 기준 95번째 백분위수의 CVE는 다른 CVE의 95%보다 악용될 가능성이 높습니다.