Description
In the Linux kernel, the following vulnerability has been resolved: mm: avoid leaving partial pfn mappings around in error case As Jann points out, PFN mappings are special, because unlike normal memory mappings, there is no lifetime information associated with the mapping - it is just a raw mapping of PFNs with no reference counting of a 'struct page'. That's all very much intentional, but it does mean that it's easy to mess up the cleanup in case of errors. Yes, a failed mmap() will always eventually clean up any partial mappings, but without any explicit lifetime in the page table mapping itself, it's very easy to do the error handling in the wrong order. In particular, it's easy to mistakenly free the physical backing store before the page tables are actually cleaned up and (temporarily) have stale dangling PTE entries. To make this situation less error-prone, just make sure that any partial pfn mapping is torn down early, before any other error handling.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
b97a50adb37e98b940a30c4656565ff609aa8f94 to < 3213fdcab961026203dd587a4533600c70b3336baffected69d4e1ce9087c8767f2fe9b9426fa2755c8e9072 to < 35770ca6180caa24a2b258c99a87bd437a1ee10faffected74ffa5a3e68504dd289135b1cf0422c19ffb3f2e to < 5b2c8b34f6d76bfbd1dd4936eb8a0fbfb9af3959affected74ffa5a3e68504dd289135b1cf0422c19ffb3f2e to < 65d0db500d7c07f0f76fc24a4d837791c4862cd2affected74ffa5a3e68504dd289135b1cf0422c19ffb3f2e to < a95a24fcaee1b892e47d5e6dcc403f713874ee80affected74ffa5a3e68504dd289135b1cf0422c19ffb3f2e to < 954fd4c81f22c4b6ba65379a81fd252971bf4ef3affected74ffa5a3e68504dd289135b1cf0422c19ffb3f2e to < 79a61cc3fc0466ad2b7b89618a6157785f0293b3affected
Linux Linux
Default version status: affected
5.13affected0 to < 5.13unaffected5.15.168 to ≤ 5.15.*unaffected6.1.111 to ≤ 6.1.*unaffected6.6.52 to ≤ 6.6.*unaffected6.10.11 to ≤ 6.10.*unaffected6.11 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/3213fdcab961026203dd587a4533600c70b3336b ↗
- https://git.kernel.org/stable/c/35770ca6180caa24a2b258c99a87bd437a1ee10f ↗
- https://git.kernel.org/stable/c/5b2c8b34f6d76bfbd1dd4936eb8a0fbfb9af3959 ↗
- https://git.kernel.org/stable/c/65d0db500d7c07f0f76fc24a4d837791c4862cd2 ↗
- https://git.kernel.org/stable/c/a95a24fcaee1b892e47d5e6dcc403f713874ee80 ↗
- https://git.kernel.org/stable/c/954fd4c81f22c4b6ba65379a81fd252971bf4ef3 ↗
- https://git.kernel.org/stable/c/79a61cc3fc0466ad2b7b89618a6157785f0293b3 ↗
- https://project-zero.issues.chromium.org/issues/366053091 ↗
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html ↗
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html ↗