CVE-2025-38496

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

dm-bufio: fix sched in atomic context

If "try_verify_in_tasklet" is set for dm-verity, DM_BUFIO_CLIENT_NO_SLEEP

is enabled for dm-bufio. However, when bufio tries to evict buffers, there

is a chance to trigger scheduling in spin_lock_bh, the following warning

is hit:

BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2745

in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 123, name: kworker/2:2

preempt_count: 201, expected: 0

RCU nest depth: 0, expected: 0

4 locks held by kworker/2:2/123:

#0: ffff88800a2d1548 ((wq_completion)dm_bufio_cache){....}-{0:0}, at: process_one_work+0xe46/0x1970

#1: ffffc90000d97d20 ((work_completion)(&dm_bufio_replacement_work)){....}-{0:0}, at: process_one_work+0x763/0x1970

#2: ffffffff8555b528 (dm_bufio_clients_lock){....}-{3:3}, at: do_global_cleanup+0x1ce/0x710

#3: ffff88801d5820b8 (&c->spinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710

Preemption

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References