CVE-2026-53265: Linux kernel · Race Condition
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in d886945fcb0f8c9dc6b39928d7a96c95c587346c : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.09% chance of exploitation in 30 days – higher than 0% 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 d886945fcb0f8c9dc6b39928d7a96c95c587346c, d3f0a606b9f278ece8a0df626ded9c4044071235, c57570fba24016ec25ec046ab44db39143fb7a64 +12
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 25 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 to a fixed release listed under Affected software.
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
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: dm cache policy smq: check allocation under invalidate lock commit 2d1f7b65f5de ("dm cache policy smq: fix missing locks in invalidating cache blocks") added mq->lock around the destructive part of smq_invalidate_mapping(), but left the e->allocated check outside the critical section. That leaves a check-then-act race. Two concurrent invalidators can both observe e->allocated as true before either of them takes mq->lock. The first invalidator that acquires the lock removes the entry from the queues and hash table and then calls free_entry(), which clears e->allocated and puts the entry back on the free list. The second invalidator can then acquire mq->lock and continue with the stale result of the unlocked check. This can corrupt the SMQ queues or hash table by deleting an entry that is no longer on those structures. It can also hit the allocation check in free_entry() when the same entry is freed again. Move the allocation check under mq->lock so the predicate and the destructive operations are serialized by the same lock.
References
- git.kernel.org/stable/c/c242c7af2aecf0b538b8623bdb86b8b441da38d9 (opens in a new tab)
- git.kernel.org/stable/c/13da856c86fb8c2ccab95034fd77da1bb2c2a17c (opens in a new tab)
- git.kernel.org/stable/c/d886945fcb0f8c9dc6b39928d7a96c95c587346c (opens in a new tab)
- git.kernel.org/stable/c/b4892561552d671bd8c4da5ebb70e9fbb1ec446e (opens in a new tab)
- git.kernel.org/stable/c/03ffe1112ed88bb3a9bd0b971549bf4d64bfc59a (opens in a new tab)
- git.kernel.org/stable/c/42ff6774ecd9d7f70d599cb71ff64373a1da4948 (opens in a new tab)
- git.kernel.org/stable/c/c57570fba24016ec25ec046ab44db39143fb7a64 (opens in a new tab)
- git.kernel.org/stable/c/d3f0a606b9f278ece8a0df626ded9c4044071235 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)