CVE-2026-53085: Linux kernel · bpf: fix mm lifecycle in open-coded task_vma iterator
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in d0862de7c866c5bd7c32531f66738c21197af888 : patch Linux kernel soon.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in d0862de7c866c5bd7c32531f66738c21197af888, d8e27d2d22b6e2df3a0125b8c08e9aace38c954c, 43683bb280330f3d36f0f2a3932a4867b9603e9c +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Linux kernel to d0862de7c866c5bd7c32531f66738c21197af888, d8e27d2d22b6e2df3a0125b8c08e9aace38c954c, 43683bb280330f3d36f0f2a3932a4867b9603e9c or 239cec25a22662dbd80f57d94b38178c8be95269.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: fix mm lifecycle in open-coded task_vma iterator The open-coded task_vma iterator reads task->mm locklessly and acquires mmap_read_trylock() but never calls mmget(). If the task exits concurrently, the mm_struct can be freed as it is not SLAB_TYPESAFE_BY_RCU, resulting in a use-after-free. Safely read task->mm with a trylock on alloc_lock and acquire an mm reference. Drop the reference via bpf_iter_mmput_async() in _destroy() and error paths. bpf_iter_mmput_async() is a local wrapper around mmput_async() with a fallback to mmput() on !CONFIG_MMU. Reject irqs-disabled contexts (including NMI) up front. Operations used by _next() and _destroy() (mmap_read_unlock, bpf_iter_mmput_async) take spinlocks with IRQs disabled (pool->lock, pi_lock). Running from NMI or from a tracepoint that fires with those locks held could deadlock. A trylock on alloc_lock is used instead of the blocking task_lock() (get_task_mm) to avoid a deadlock when a softirq BPF program iterates a task that already holds its alloc_lock on the same CPU.
References
- git.kernel.org/stable/c/239cec25a22662dbd80f57d94b38178c8be95269 (opens in a new tab)
- git.kernel.org/stable/c/d0862de7c866c5bd7c32531f66738c21197af888 (opens in a new tab)
- git.kernel.org/stable/c/43683bb280330f3d36f0f2a3932a4867b9603e9c (opens in a new tab)
- git.kernel.org/stable/c/d8e27d2d22b6e2df3a0125b8c08e9aace38c954c (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-53085 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2492404 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53085.json (opens in a new tab)