| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: 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). |
| |
| The Linux kernel CVE team has assigned CVE-2025-21691 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.5 with commit cf264e1329fb0307e044f7675849f9f38b44c11a and fixed in 6.6.75 with commit 7d6405c13b0d8a8367cd8df63f118b619a3f0dd2 |
| Issue introduced in 6.5 with commit cf264e1329fb0307e044f7675849f9f38b44c11a and fixed in 6.12.12 with commit 780ab8329672464984cf1344bd5c3993af0226c7 |
| Issue introduced in 6.5 with commit cf264e1329fb0307e044f7675849f9f38b44c11a and fixed in 6.13.1 with commit 97153a05077f618f7471f50a78158602badccb30 |
| Issue introduced in 6.5 with commit cf264e1329fb0307e044f7675849f9f38b44c11a and fixed in 6.14 with commit 5f537664e705b0bf8b7e329861f20128534f6a83 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-21691 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| mm/filemap.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| 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 |
