Race condition in Linux kernel - CVE-2026-72121
Published: August 16, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a race condition in net/can/bcm.c when updating filter and timer values concurrently with handling incoming CAN traffic. A local user can trigger concurrent bcm_rx_setup() and RX handler activity to cause a denial of service.
The issue affects concurrent access to timer, filter, and stored frame state in the broadcast manager CAN implementation.
Affected software
Ubuntu
linux-nvidia (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
How to mitigate CVE-2026-72121
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
External References
- https://git.kernel.org/stable/c/19b1994069dd29478ba767de1f98f14a088198dc
- https://git.kernel.org/stable/c/749179c2e25b95d22499ed29096b3e02d6dfd2b4
- https://git.kernel.org/stable/c/834cbca3b12e46887f7a9b35f1981a888360ea4c
- https://git.kernel.org/stable/c/a7eb6db1cd3f7b556a301dc1265945ad112089f7
- https://git.kernel.org/stable/c/fc9f5ee1b073bd233d9c604e338af4ebb42cbc33