bpf: Fix use-after-free on mm_struct in bpf_find_vma()
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 · fixed in db347840d6b6ee9bb9b8e4a985d4b4419f9f3200; From 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 · fixed in 8e1101fc4118019a69c96ced4aec93164f89cbd5; From 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 · fixed in c7ad910e987008e125eeff448892e86852173384; From 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 · fixed in 86d54cf069fc5ae2e111c87933bebf6eb527978e; From 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 · fixed in 2b2a903bee56d312539046d9defa8023eec94760; From 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 · fixed in 47b079e2117a2ee52e21f8b72935900c702fc0b5
- Linux Linux
5.17
- KernelLinux
From 5.17.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6