Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: cachestat: fix page cache statistics permission checking When the 'cachestat()' system call was added in commit cf264e1329fb ("cachestat: implement cachestat syscall"), it was meant to be a much more convenient (and performant) version of mincore() that didn't need mapping things into the user virtual address space in order to work. But it ended up missing the "check for writability or ownership" fix for mincore(), done in commit 134fca9063ad ("mm/mincore.c: make mincore() more conservative"). This just adds equivalent logic to 'cachestat()', modified for the file context (rather than vma).
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.5, < 6.6.75 |
References
- https://git.kernel.org/stable/c/5f537664e705b0bf8b7e329861f20128534f6a83Patch
- https://git.kernel.org/stable/c/780ab8329672464984cf1344bd5c3993af0226c7Patch
- https://git.kernel.org/stable/c/7d6405c13b0d8a8367cd8df63f118b619a3f0dd2Patch
- https://git.kernel.org/stable/c/97153a05077f618f7471f50a78158602badccb30Patch
FAQ
What is CVE-2025-21691?
CVE-2025-21691 is a vulnerability with a CVSS score of 5.5 (MEDIUM). In the Linux kernel, the following vulnerability has been resolved: cachestat: fix page cache statistics permission checking When the 'cachestat()' system call was added in commit cf264e1329fb ("cac...
How severe is CVE-2025-21691?
CVE-2025-21691 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-21691?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.