| Release Date: | 2026-09-17 | |
| Impact: | Low | What is this? |
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix use-after-free on mm_struct in bpf_find_vma() bpf_find_vma() reads task->mm and calls mmap_read_trylock(mm) without holding a reference on the mm. On a foreign task, a concurrent exit_mm() can free the mm_struct between the lockless read and the trylock, resulting in a use-after-free. mm_struct is not SLAB_TYPESAFE_BY_RCU. For the current task, task->mm is stable. For a foreign task, pin the mm under task->alloc_lock and release it with mmput_async(), mirroring commit d8e27d2d22b6 ("bpf: fix mm lifecycle in open-coded task_vma iterator"). Use spin_trylock() instead of get_task_mm() so BPF context does not block on alloc_lock. Reject irqs-disabled contexts and !CONFIG_MMU on the foreign-task path because dropping the mm reference is not safe there. Race: CPU0 (BPF program) CPU1 (exiting task) ============================ ========================== bpf_find_vma(foreign_task): mm = task->mm exit_mm(): task->mm = NULL mmput(mm) -> frees mm_struct mmap_read_trylock(mm) // UAF on mm
See more information about CVE-2026-93137 from MITRE CVE dictionary and NIST NVD
NOTE: The following CVSS metrics and score provided are preliminary and subject to review.
| Base Score: | 6.7 |
| Vector String: | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
| Version: | 3.1 |
| Attack Vector: | Local |
| Attack Complexity: | Low |
| Privileges Required: | High |
| User Interaction: | None |
| Scope: | Unchanged |
| Confidentiality Impact: | High |
| Integrity Impact: | High |
| Availability Impact: | High |
| Platform | Errata | Release Date |
| Oracle Linux version 9 (kernel-uek) | ELSA-2026-500374 | 2026-10-07 |
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