CVE-2026-89580

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

Description An out-of-bounds write exists in the bpf get stack() function. In preemptible BPF programs running on a PREEMPT kernel, a task can be scheduled out after obtaining a per-CPU perf callchain entry buffer but before the data is copied. If another task on the same CPU reuses this buffer and increases the trace->nr value, the subsequent memcpy() operation can exceed the caller's buffer size. This occurs because the rcu read lock() does not disable preemption under CONFIG PREEMPT RCU, allowing the buffer to be overwritten. This issue can lead to local privilege escalation.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.