bpf: Fix use-after-free on mm_struct in bpf_find_vma()
Summary
| CVE | CVE-2026-93137 |
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| State | PUBLISHED |
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| Assigner | Linux |
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| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-09-17 17:18:08 UTC |
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| Updated | 2026-09-17 17:18:08 UTC |
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| Description | 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 |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 db347840d6b6ee9bb9b8e4a985d4b4419f9f3200 git |
Not specified |
| CNA |
Linux |
Linux |
affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 8e1101fc4118019a69c96ced4aec93164f89cbd5 git |
Not specified |
| CNA |
Linux |
Linux |
affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 c7ad910e987008e125eeff448892e86852173384 git |
Not specified |
| CNA |
Linux |
Linux |
affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 86d54cf069fc5ae2e111c87933bebf6eb527978e git |
Not specified |
| CNA |
Linux |
Linux |
affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 2b2a903bee56d312539046d9defa8023eec94760 git |
Not specified |
| CNA |
Linux |
Linux |
affected 7c7e3d31e7856a8260a254f8c71db416f7f9f5a1 47b079e2117a2ee52e21f8b72935900c702fc0b5 git |
Not specified |
| CNA |
Linux |
Linux |
affected 5.17 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.17 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.1.188 6.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.157 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.110 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.52 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.6 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3-rc1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/86d54cf069fc5ae2e111c87933bebf6eb527978e |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/47b079e2117a2ee52e21f8b72935900c702fc0b5 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/db347840d6b6ee9bb9b8e4a985d4b4419f9f3200 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/c7ad910e987008e125eeff448892e86852173384 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/8e1101fc4118019a69c96ced4aec93164f89cbd5 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/2b2a903bee56d312539046d9defa8023eec94760 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.