CVE-2025-21691

Summary

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).

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxcf264e1329fb0307e044f7675849f9f38b44c11a < 7d6405c13b0d8a8367cd8df63f118b619a3f0dd2affected
LinuxLinuxcf264e1329fb0307e044f7675849f9f38b44c11a < 780ab8329672464984cf1344bd5c3993af0226c7affected
LinuxLinuxcf264e1329fb0307e044f7675849f9f38b44c11a < 97153a05077f618f7471f50a78158602badccb30affected
LinuxLinuxcf264e1329fb0307e044f7675849f9f38b44c11a < 5f537664e705b0bf8b7e329861f20128534f6a83affected
LinuxLinux6.5affected
LinuxLinux0 < 6.5unaffected
LinuxLinux6.6.75 <= 6.6.*unaffected
LinuxLinux6.12.12 <= 6.12.*unaffected
LinuxLinux6.13.1 <= 6.13.*unaffected
LinuxLinux6.14 <= *unaffected

Weaknesses

References