{"id":"CVE-2025-38496","summary":"dm-bufio: fix sched in atomic context","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm-bufio: fix sched in atomic context\n\nIf \"try_verify_in_tasklet\" is set for dm-verity, DM_BUFIO_CLIENT_NO_SLEEP\nis enabled for dm-bufio. However, when bufio tries to evict buffers, there\nis a chance to trigger scheduling in spin_lock_bh, the following warning\nis hit:\n\nBUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2745\nin_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 123, name: kworker/2:2\npreempt_count: 201, expected: 0\nRCU nest depth: 0, expected: 0\n4 locks held by kworker/2:2/123:\n #0: ffff88800a2d1548 ((wq_completion)dm_bufio_cache){....}-{0:0}, at: process_one_work+0xe46/0x1970\n #1: ffffc90000d97d20 ((work_completion)(&dm_bufio_replacement_work)){....}-{0:0}, at: process_one_work+0x763/0x1970\n #2: ffffffff8555b528 (dm_bufio_clients_lock){....}-{3:3}, at: do_global_cleanup+0x1ce/0x710\n #3: ffff88801d5820b8 (&c-\u003espinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710\nPreemption disabled at:\n[\u003c0000000000000000\u003e] 0x0\nCPU: 2 UID: 0 PID: 123 Comm: kworker/2:2 Not tainted 6.16.0-rc3-g90548c634bd0 #305 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014\nWorkqueue: dm_bufio_cache do_global_cleanup\nCall Trace:\n \u003cTASK\u003e\n dump_stack_lvl+0x53/0x70\n __might_resched+0x360/0x4e0\n do_global_cleanup+0x2f5/0x710\n process_one_work+0x7db/0x1970\n worker_thread+0x518/0xea0\n kthread+0x359/0x690\n ret_from_fork+0xf3/0x1b0\n ret_from_fork_asm+0x1a/0x30\n \u003c/TASK\u003e\n\nThat can be reproduced by:\n\n  veritysetup format --data-block-size=4096 --hash-block-size=4096 /dev/vda /dev/vdb\n  SIZE=$(blockdev --getsz /dev/vda)\n  dmsetup create myverity -r --table \"0 $SIZE verity 1 /dev/vda /dev/vdb 4096 4096 \u003cdata_blocks\u003e 1 sha256 \u003croot_hash\u003e \u003csalt\u003e 1 try_verify_in_tasklet\"\n  mount /dev/dm-0 /mnt -o ro\n  echo 102400 \u003e /sys/module/dm_bufio/parameters/max_cache_size_bytes\n  [read files in /mnt]","modified":"2026-03-20T12:42:53.376563Z","published":"2025-07-28T11:22:05.091Z","related":["MGASA-2025-0218","MGASA-2025-0219","SUSE-SU-2025:02853-1","SUSE-SU-2025:02923-1","SUSE-SU-2025:02969-1","SUSE-SU-2025:02996-1","SUSE-SU-2025:02997-1","SUSE-SU-2025:03011-1","SUSE-SU-2025:03023-1","SUSE-SU-2025:20577-1","SUSE-SU-2025:20586-1","SUSE-SU-2025:20601-1","SUSE-SU-2025:20602-1","SUSE-SU-2025:21074-1","SUSE-SU-2025:21139-1","SUSE-SU-2025:21179-1","openSUSE-SU-2025:20081-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38496.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3edfdb1d4ef81320dae0caa40bc24baf8c1bbb86"},{"type":"WEB","url":"https://git.kernel.org/stable/c/469a39a33a9934af157299bf11c58f6e6cb53f85"},{"type":"WEB","url":"https://git.kernel.org/stable/c/68860d1ade385eef9fcdbf6552f061283091fdb8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b1bf1a782fdf5c482215c0c661b5da98b8e75773"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38496.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38496"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"450e8dee51aa6fa1dd0f64073e88235f1a77b035"},{"fixed":"469a39a33a9934af157299bf11c58f6e6cb53f85"},{"fixed":"68860d1ade385eef9fcdbf6552f061283091fdb8"},{"fixed":"3edfdb1d4ef81320dae0caa40bc24baf8c1bbb86"},{"fixed":"b1bf1a782fdf5c482215c0c661b5da98b8e75773"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-38496.json"}}],"schema_version":"1.7.5"}