CVE-2025-40218
In the Linux kernel, the following vulnerability has been resolved: mm/damon/vaddr: do not repeat pte_offset_map_lock() until success DAMON's virtual address space operation set implementation (vaddr) calls pte_offset_map_lock() inside the page table walk callback function. This is for reading and writing page table accessed bits. If pte_offset_map_lock() fails, it retries by returning the page table walk callback function with ACTION_AGAIN. pte_offset_map_lock() can continuously fail if the target is a pmd migration entry, though. Hence it could cause an infinite page table walk if the migration cannot be done until the page table walk is finished. This indeed caused a soft lockup when CPU hotplugging and DAMON were running in parallel. Avoid the infinite loop by simply not retrying the page table walk. DAMON is promising only a best-effort accuracy, so missing access to such pages is no problem.
Affected versions
Linux kernel versions
6.5
and later are affected. Fixed in
6.6.113,
6.12.54,
6.17.4,
6.18
and their respective stable series.
References
The following references provide additional information about CVE-2025-40218 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/0ccd91cf749536d41307a07e60ec14ab0dbf21f5
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PatchKernel patch commithttps://git.kernel.org/stable/c/677ebfe5d00f94adec0c0204f6e6e2a82d3f77bf
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PatchKernel patch commithttps://git.kernel.org/stable/c/ac42320ec873bfe726141069cfdd90ee5bc4e885
Frequently asked questions
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What is CVE-2025-40218?
CVE-2025-40218 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.5 onward and has been patched in 6.6.113, 6.12.54, 6.17.4 and others. CVE-2025-40218 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2025-40218?
Yes — CVE-2025-40218 has been patched. Fixed versions include 6.6.113, 6.12.54, 6.17.4 and others. If you are running Linux kernel 6.5 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-40218 actively exploited?
No — CVE-2025-40218 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.