CVE-2025-38496

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> dm-bufio: fix sched in atomic context<br /> <br /> If "try_verify_in_tasklet" is set for dm-verity, DM_BUFIO_CLIENT_NO_SLEEP<br /> is enabled for dm-bufio. However, when bufio tries to evict buffers, there<br /> is a chance to trigger scheduling in spin_lock_bh, the following warning<br /> is hit:<br /> <br /> BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2745<br /> in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 123, name: kworker/2:2<br /> preempt_count: 201, expected: 0<br /> RCU nest depth: 0, expected: 0<br /> 4 locks held by kworker/2:2/123:<br /> #0: ffff88800a2d1548 ((wq_completion)dm_bufio_cache){....}-{0:0}, at: process_one_work+0xe46/0x1970<br /> #1: ffffc90000d97d20 ((work_completion)(&amp;dm_bufio_replacement_work)){....}-{0:0}, at: process_one_work+0x763/0x1970<br /> #2: ffffffff8555b528 (dm_bufio_clients_lock){....}-{3:3}, at: do_global_cleanup+0x1ce/0x710<br /> #3: ffff88801d5820b8 (&amp;c-&gt;spinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710<br /> Preemption disabled at:<br /> [] 0x0<br /> CPU: 2 UID: 0 PID: 123 Comm: kworker/2:2 Not tainted 6.16.0-rc3-g90548c634bd0 #305 PREEMPT(voluntary)<br /> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014<br /> Workqueue: dm_bufio_cache do_global_cleanup<br /> Call Trace:<br /> <br /> dump_stack_lvl+0x53/0x70<br /> __might_resched+0x360/0x4e0<br /> do_global_cleanup+0x2f5/0x710<br /> process_one_work+0x7db/0x1970<br /> worker_thread+0x518/0xea0<br /> kthread+0x359/0x690<br /> ret_from_fork+0xf3/0x1b0<br /> ret_from_fork_asm+0x1a/0x30<br /> <br /> <br /> That can be reproduced by:<br /> <br /> veritysetup format --data-block-size=4096 --hash-block-size=4096 /dev/vda /dev/vdb<br /> SIZE=$(blockdev --getsz /dev/vda)<br /> dmsetup create myverity -r --table "0 $SIZE verity 1 /dev/vda /dev/vdb 4096 4096 1 sha256 1 try_verify_in_tasklet"<br /> mount /dev/dm-0 /mnt -o ro<br /> echo 102400 &gt; /sys/module/dm_bufio/parameters/max_cache_size_bytes<br /> [read files in /mnt]