CVE-2025-21691

cachestat: fix page cache statistics permission checking

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).

N/A

CVSS

Severity:

EPSS 0.03%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/7d6405c13b0d8a8367cd8df63f118b619a3f0dd2
https://git.kernel.org/stable/c/780ab8329672464984cf1344bd5c3993af0226c7
https://git.kernel.org/stable/c/97153a05077f618f7471f50a78158602badccb30
https://git.kernel.org/stable/c/5f537664e705b0bf8b7e329861f20128534f6a83

Frequently Asked Questions

What is the severity of CVE-2025-21691?: CVE-2025-21691 has not yet been assigned a CVSS score.
How to fix CVE-2025-21691?: To fix CVE-2025-21691, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-21691 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2025-21691 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-21691?: CVE-2025-21691 affects Linux Linux, Linux Linux.

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