CVE-2026-90393

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A race condition exists in the bpf netns link update prog() function. The issue occurs because checks for old prog and program type are performed without locking before the netns bpf mutex is acquired. If two threads concurrently execute BPF LINK UPDATE on the same network namespace link, it can lead to a Use-After-Free (UAF) condition, which happens when a program continues to use a memory pointer after it has been freed.

Recommendations Move the old prog and prog->type checks inside the netns bpf mutex critical section.