Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected eac9153f2b584c702cea02c1f1a57d85aa9aea42 before b6c9daf6097f9b39162b8e736a6ac7caf5ef6fc8; affected eac9153f2b584c702cea02c1f1a57d85aa9aea42 before 931f62311c058d79f29548f20943969bb441ce87; affected eac9153f2b584c702cea02c1f1a57d85aa9aea42 before a052ad5edccf5319f50ed955de4368f8318a9f20; affected eac9153f2b584c702cea02c1f1a57d85aa9aea42 before 051f2da26ce377f683b938a3382e0f16d02f3139; affected eac9153f2b584c702cea02c1f1a57d85aa9aea42 before fa9dcacdcdf487f0ffef64bf67622f1caed509f1; affected a7f4da875c16f3b8bef0d9ec67528111045bfcd8; affected f1838da73cccb238b8be4ef464fce0168dc7ba84; affected 4.19.92 before 4.20; affected 5.4.7 before 5.5 |
| Linux / Linux | affected 5.5; unaffected 0 before 5.5; unaffected 6.6.160 through 6.6.*; unaffected 6.12.114 through 6.12.*; unaffected 6.18.52 through 6.18.*; unaffected 7.2.6 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/b6c9daf6097f9b39162b8e736a6ac7caf5ef6fc8
- https://git.kernel.org/stable/c/931f62311c058d79f29548f20943969bb441ce87
- https://git.kernel.org/stable/c/a052ad5edccf5319f50ed955de4368f8318a9f20
- https://git.kernel.org/stable/c/051f2da26ce377f683b938a3382e0f16d02f3139
- https://git.kernel.org/stable/c/fa9dcacdcdf487f0ffef64bf67622f1caed509f1