Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix mmap_lock leak in irq_work path
stack_map_get_build_id_offset() introduced a per-CPU irq_work to defer mmap_read_unlock() from NMI context, and bpf_find_vma() later reused the same mmap_unlock_work. Both callers only check whether the work is busy before taking mmap_lock, so a nested caller can reuse the slot before the first caller queues it. Two read locks may then be acquired while only one deferred unlock runs, leaking a read lock and blocking exit_mmap().
Reserve the per-CPU slot before mmap_read_trylock(). Use the same wrapper in stackmap and bpf_find_vma() so both callers release the reservation on trylock failure. Keep rejecting the slot while the irq_work remains busy. Release it after the irq_work callback unlocks the mm.
Metrics
No CVSS score has been published yet.
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= eac9153f2b584c702cea02c1f1a57d85aa9aea42, < d6d091873e12d1de36d7228c4f452e6cace3a23e; >= eac9153f2b584c702cea02c1f1a57d85aa9aea42, < b6c9daf6097f9b39162b8e736a6ac7caf5ef6fc8; >= eac9153f2b584c702cea02c1f1a57d85aa9aea42, < 931f62311c058d79f29548f20943969bb441ce87; >= eac9153f2b584c702cea02c1f1a57d85aa9aea42, < a052ad5edccf5319f50ed955de4368f8318a9f20; >= eac9153f2b584c702cea02c1f1a57d85aa9aea42, < 051f2da26ce377f683b938a3382e0f16d02f3139; >= eac9153f2b584c702cea02c1f1a57d85aa9aea42, < fa9dcacdcdf487f0ffef64bf67622f1caed509f1; a7f4da875c16f3b8bef0d9ec67528111045bfcd8; f1838da73cccb238b8be4ef464fce0168dc7ba84; >= 4.19.92, < 4.20; >= 5.4.7, < 5.5 |
| Linux | Linux | 5.5 |
References
- https://git.kernel.org/stable/c/051f2da26ce377f683b938a3382e0f16d02f3139
- https://git.kernel.org/stable/c/931f62311c058d79f29548f20943969bb441ce87
- https://git.kernel.org/stable/c/a052ad5edccf5319f50ed955de4368f8318a9f20
- https://git.kernel.org/stable/c/b6c9daf6097f9b39162b8e736a6ac7caf5ef6fc8
- https://git.kernel.org/stable/c/d6d091873e12d1de36d7228c4f452e6cace3a23e
- https://git.kernel.org/stable/c/fa9dcacdcdf487f0ffef64bf67622f1caed509f1
Timeline
- Published
- Sep 17, 2026
- Last modified
- Oct 30, 2026
- NVD status
- Received