cbcvebase.
CVE-2025-38496
published 2025-07-28

CVE-2025-38496: 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…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.14%
3.7th percentile
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 disabled at: [] 0x0 CPU: 2 UID: 0 PID: 123 Comm: kworker/2:2 Not tainted 6.16.0-rc3-g90548c634bd0 #305 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 Workqueue: dm_bufio_cache do_global_cleanup Call Trace: dump_stack_lvl+0x53/0x70 __might_resched+0x360/0x4e0 do_global_cleanup+0x2f5/0x710 process_one_work+0x7db/0x1970 worker_thread+0x518/0xea0 kthread+0x359/0x690 ret_from_fork+0xf3/0x1b0 ret_from_fork_asm+0x1a/0x30 That can be reproduced by: veritysetup format --data-block-size=4096 --hash-block-size=4096 /dev/vda /dev/vdb SIZE=$(blockdev --getsz /dev/vda) dmsetup create myverity -r --table "0 $SIZE verity 1 /dev/vda /dev/vdb 4096 4096 1 sha256 1 try_verify_in_tasklet" mount /dev/dm-0 /mnt -o ro echo 102400 > /sys/module/dm_bufio/parameters/max_cache_size_bytes [read files in /mnt]

Affected

24 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.16.3-1 (forky)linux 6.16.3-1 (forky)
linuxlinux
linuxlinux>= 450e8dee51aa6fa1dd0f64073e88235f1a77b035 < 469a39a33a9934af157299bf11c58f6e6cb53f85469a39a33a9934af157299bf11c58f6e6cb53f85
linuxlinux>= 450e8dee51aa6fa1dd0f64073e88235f1a77b035 < 68860d1ade385eef9fcdbf6552f061283091fdb868860d1ade385eef9fcdbf6552f061283091fdb8
linuxlinux>= 450e8dee51aa6fa1dd0f64073e88235f1a77b035 < 3edfdb1d4ef81320dae0caa40bc24baf8c1bbb863edfdb1d4ef81320dae0caa40bc24baf8c1bbb86
linuxlinux>= 450e8dee51aa6fa1dd0f64073e88235f1a77b035 < b1bf1a782fdf5c482215c0c661b5da98b8e75773b1bf1a782fdf5c482215c0c661b5da98b8e75773
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.41-16.12.41-1
linuxlinux_kernel>= 0 < 6.16.3-16.16.3-1
linuxlinux_kernel>= 0 < 6.8.0-100.1006.8.0-100.100
linuxlinux_kernel>= 6.13 < 6.15.86.15.8
linuxlinux_kernel>= 6.4 < 6.6.1006.6.100
linuxlinux_kernel>= 6.7 < 6.12.406.12.40
msrcazl3_kernel_6.6.96.2-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.96.2-2_on_azure_linux_3.0
ubuntulinux-aws
ubuntulinux-aws-6.8
ubuntulinux-gkeop
ubuntulinux-nvidia
ubuntulinux-nvidia-6.8
ubuntulinux-oracle
ubuntulinux-oracle-6.8
ubuntulinux-raspi-realtime
ubuntulinux-realtime

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
vendor_msrc4.7MEDIUM
vendor_ubuntu3.2LOW
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