Use-after-free in Linux kernel - CVE-2026-74401
Published: August 15, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in the DLM send_queue handling in fs/dlm/midcomms.c when processing a high volume of DLM messages. A local user can trigger heavy DLM message activity to cause a denial of service.
The issue occurs when message sequence numbers in the ordered send queue are not assigned in the required order, leading to refcounting problems.
Affected software
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
How to mitigate CVE-2026-74401
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14
External References
- https://git.kernel.org/stable/c/4d45250b1d22960f86d83245be188b16e456218b
- https://git.kernel.org/stable/c/6369619f1b665f12d8c99cc6ff733c64eb08b22e
- https://git.kernel.org/stable/c/712714f818d83373847874ab0f8e426be79296cf
- https://git.kernel.org/stable/c/ae9e534e502a0f48c12baf83608c5de0ff0eab11
- https://git.kernel.org/stable/c/d2248cb70c070f8f04762872772e155b59016f17