NULL pointer dereference in Linux kernel - CVE-2026-64094
Published: July 20, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a NULL pointer dereference in batman-adv bridge loop avoidance claim handling in net/batman-adv/bridge_loop_avoidance.c when sending an ARP request after a primary interface is decoupled from its mesh interface. A local user can trigger this race condition to cause a denial of service.
The issue occurs when the primary hard interface is accessed without rtnl_lock held and its mesh interface pointer becomes NULL during the operation.
Affected software
Ubuntu
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
How to mitigate CVE-2026-64094
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16
External References
- https://git.kernel.org/stable/c/0f3ebd7bb417aabc44853cc7c2a184ebb0e05b45
- https://git.kernel.org/stable/c/2a8c9e86529156c62d9187b9ed9454c31665ad33
- https://git.kernel.org/stable/c/4f6266735a0ba6a568b6d4c9fa51c33a5a7f2d70
- https://git.kernel.org/stable/c/53cb3511f6eda37d3bd923545fdba6013b6d7bb7
- https://git.kernel.org/stable/c/555b8d3f5c313d81d46274fd0976352dafc80124
- https://git.kernel.org/stable/c/6921a7683ae9ad0208d829e71f725a9e25ccff49
- https://git.kernel.org/stable/c/efb62458c94db1fe3a287e7e89c31b0cfb03f938
- https://git.kernel.org/stable/c/f80d3d98d2ff78d9e2fe5d68b1f45948c4f7bd24