Time-of-check Time-of-use (TOCTOU) Race Condition in Linux kernel - CVE-2026-53265
Published: June 26, 2026
Vulnerability identifier: #VU135487
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-53265
CWE-ID: CWE-367
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a check-then-act race condition in smq_invalidate_mapping() in the dm-cache-policy-smq component when invalidating cache blocks concurrently. A local user can trigger concurrent invalidation operations to cause a denial of service.
The issue can corrupt the SMQ queues or hash table and may result in a double free condition.
How to mitigate CVE-2026-53265
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/03ffe1112ed88bb3a9bd0b971549bf4d64bfc59a
- https://git.kernel.org/stable/c/13da856c86fb8c2ccab95034fd77da1bb2c2a17c
- https://git.kernel.org/stable/c/42ff6774ecd9d7f70d599cb71ff64373a1da4948
- https://git.kernel.org/stable/c/b4892561552d671bd8c4da5ebb70e9fbb1ec446e
- https://git.kernel.org/stable/c/c242c7af2aecf0b538b8623bdb86b8b441da38d9
- https://git.kernel.org/stable/c/c57570fba24016ec25ec046ab44db39143fb7a64
- https://git.kernel.org/stable/c/d3f0a606b9f278ece8a0df626ded9c4044071235
- https://git.kernel.org/stable/c/d886945fcb0f8c9dc6b39928d7a96c95c587346c