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).

https://git.kernel.org/stable/c/5f537664e705b0bf8b7e329861f20128534f6a83

https://git.kernel.org/stable/c/780ab8329672464984cf1344bd5c3993af0226c7

https://git.kernel.org/stable/c/7d6405c13b0d8a8367cd8df63f118b619a3f0dd2

https://git.kernel.org/stable/c/97153a05077f618f7471f50a78158602badccb30