CVE: CVE-2025-37928
Published: 2025-05-20
Description: In the Linux kernel, the following vulnerability has been resolved:

dm-bufio: don't schedule in atomic context

A BUG was reported as below when CONFIG_DEBUG_ATOMIC_SLEEP and
try_verify_in_tasklet are enabled.
[  129.444685][  T934] BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2421
[  129.444723][  T934] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 934, name: kworker/1:4
[  129.444740][  T934] preempt_count: 201, expected: 0
[  129.444756][  T934] RCU nest depth: 0, expected: 0
[  129.444781][  T934] Preemption disabled at:
[  129.444789][  T934] [<ffffffd816231900>] shrink_work+0x21c/0x248
[  129.445167][  T934] kernel BUG at kernel/sched/walt/walt_debug.c:16!
[  129.445183][  T934] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
[  129.445204][  T934] Skip md ftrace buffer dump for: 0x1609e0
[  129.447348][  T934] CPU: 1 PID: 934 Comm: kworker/1:4 Tainted: G        W  OE      6.6.56-android15-8-o-g6f82312b30b9-debug #[PII_REDACTED]000000474e5500b[PII_REDACTED]464e8
[  129.447362][  T934] Hardware name: Qualcomm Technologies, Inc. Parrot QRD, Alpha-M (DT)
[  129.447373][  T934] Workqueue: dm_bufio_cache shrink_work
[  129.447394][  T934] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  129.447406][  T934] pc : android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug]
[  129.447435][  T934] lr : __traceiter_android_rvh_schedule_bug+0x44/0x6c
[  129.447451][  T934] sp : ffffffc0843dbc90
[  129.447459][  T934] x29: ffffffc0843dbc90 x28: ffffffffffffffff x27:[PII_REDACTED]000c8b
[  129.447479][  T934] x26: [PII_REDACTED] x25: ffffff804b3d6260 x24: ffffffd816232b68
[  129.447497][  T934] x23: ffffff805171c5b4 x22: [PII_REDACTED] x21: ffffffd816231900
[  129.447517][  T934] x20: ffffff80306ba898 x19: [PII_REDACTED] x18: ffffffc084159030
[  129.447535][  T934] x17: 00000000d2b5dd1f x16: 00000000d2b5dd1f x15: ffffffd816720358
[  129.447554][  T934] x14: [PII_REDACTED] x13: ffffff89ef978000 x12: [PII_REDACTED]
[  129.447572][  T934] x11: ffffffd817a823c4 x10: [PII_REDACTED] x9 : 7e779c5735de9400
[  129.447591][  T934] x8 : ffffffd81560d004 x7 : 205b5d[PII_REDACTED] x6 : ffffffd8167397c8
[  129.447610][  T934] x5 : [PII_REDACTED] x4 : [PII_REDACTED] x3 : ffffffc0843db9e0
[  129.447629][  T934] x2 :[PII_REDACTED]002f15 x1 : [PII_REDACTED] x0 : [PII_REDACTED]
[  129.447647][  T934] Call trace:
[  129.447655][  T934]  android_rvh_schedule_bug+0x0/0x8 [sched_walt_debug[PII_REDACTED]000000474e550080cce8a8a78606b6]
[  129.447681][  T934]  __might_resched+0x190/0x1a8
[  129.447694][  T934]  shrink_work+0x180/0x248
[  129.447706][  T934]  process_one_work+0x260/0x624
[  129.447718][  T934]  worker_thread+0x28c/0x454
[  129.447729][  T934]  kthread+0x118/0x158
[  129.447742][  T934]  ret_from_fork+0x10/0x20
[  129.447761][  T934] Code: ???????? ???????? ???????? d2b5dd1f (d4210000)
[  129.447772][  T934] ---[ end trace [PII_REDACTED] ]---

dm_bufio_lock will call spin_lock_bh when try_verify_in_tasklet
is enabled, and __scan will be called in atomic context.
CVSS Score: 7.8 (HIGH)
References: https://git.kernel.org/stable/c/69a37b3ba85088fc6b903b8e1db7f0a1d4d0b52d; https://git.kernel.org/stable/c/a3d8f0a7f5e8b193db509c7191fefeed3533fc44; https://git.kernel.org/stable/c/a99f5bf4f[PII_REDACTED]dbce14c12f8e2ce5a5a69