CVE-2022-48991
mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths
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mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths
In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths Any codepath that zaps page table entries must invoke MMU notifiers to ensure that secondary MMUs (like KVM) don't keep accessing pages which aren't mapped anymore. Secondary MMUs don't hold their own references to pages that are mirrored over, so failing to notify them can lead to page use-after-free. I'm marking this as addressing an issue introduced in commit f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages"), but most of the security impact of this only came in commit 27e1f8273113 ("khugepaged: enable collapse pmd for pte-mapped THP"), which actually omitted flushes for the removal of present PTEs, not just for the removal of empty page tables.
Reserved 2024-08-22 | Published 2024-10-21 | Updated 2024-12-19 | Assigner Linuxgit.kernel.org/...c/275c626c131cfe141beeb6c575e31fa53d32da19
git.kernel.org/...c/c23105673228c349739e958fa33955ed8faddcaf
git.kernel.org/...c/ff2a1a6f869650aec99e9d070b5ab625bfbc5bc3
git.kernel.org/...c/5ffc2a75534d9d74d49760f983f8eb675fa63d69
git.kernel.org/...c/7f445ca2e0e59c7971d0b7b853465e50844ab596
git.kernel.org/...c/1a3f8c6cd29d9078cc81b29d39d0e9ae1d6a03c3
git.kernel.org/...c/5450535901d89a5dcca5fbbc59a24fe89caeb465
git.kernel.org/...c/f268f6cf875f3220afc77bdd0bf1bb136eb54db9
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