← CVE Intelligence

CVE-2026-93137

bpf: Fix use-after-free on mm_struct in bpf_find_vma() PUBLISHED

Description (CNA)

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

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 before db347840d6b6ee9bb9b8e4a985d4b4419f9f3200; affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 before 8e1101fc4118019a69c96ced4aec93164f89cbd5; affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 before c7ad910e987008e125eeff448892e86852173384; affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 before 86d54cf069fc5ae2e111c87933bebf6eb527978e; affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 before 2b2a903bee56d312539046d9defa8023eec94760; affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 before 47b079e2117a2ee52e21f8b72935900c702fc0b5
Linux / Linuxaffected 5.17; unaffected 0 before 5.17; unaffected 6.1.188 through 6.1.*; unaffected 6.6.157 through 6.6.*; unaffected 6.12.110 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