CVE Catalog

CVE-2026-90317

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.15%

5th percentile - higher than 5% of all known CVEs

Summary

In the Linux kernel, in sleepable BPF programs a spin lock can be the only RCU protection for a kptr. After the final bpf_spin_unlock() the verifier leaves the pointer valid, allowing another CPU to free the object before use, causing a use-after-free (e.g. in __bpf_get_task_stack()).

Risk Assessment

A local attacker with limited privileges can trigger a kernel use-after-free, potentially leading to privilege escalation or system crash.

Recommendation

Update the Linux kernel to a version containing the fix that invalidates RCU-protected pointers after the final spin unlock.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: bpf: Invalidate RCU pointers after final spin unlock In a sleepable BPF program, a spin lock can provide the only RCU protection for a kptr. The final bpf_spin_unlock() ends that protection, but the verifier leaves the pointer valid. Another CPU can then free the object before the pointer is used. A capability-limited runtime PoC triggered a task_struct use-after-free in __bpf_get_task_stack(). Record whether the program is in an RCU-protected context before releasing the lock. Invalidate RCU-protected pointers only when the unlock leaves the final such context. This preserves valid pointers in non-sleepable programs and inside an explicit RCU read-side section.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS