CVE-2026-90317

unknown
EUVD alias: EUVD-2026-81978
Assigned by CNA: linux
Published 2026-09-17 · Modified 2026-09-17
CVSS v3
CVSS v4 NEW
not yet in upstream
VIR risk

Description

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.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.