Description
In the Linux kernel, the following vulnerability has been resolved: x86/mm: Fix flush_tlb_range() when used for zapping normal PMDs On the following path, flush_tlb_range() can be used for zapping normal PMD entries (PMD entries that point to page tables) together with the PTE entries in the pointed-to page table: collapse_pte_mapped_thp pmdp_collapse_flush flush_tlb_range The arm64 version of flush_tlb_range() has a comment describing that it can be used for page table removal, and does not use any last-level invalidation optimizations. Fix the X86 version by making it behave the same way. Currently, X86 only uses this information for the following two purposes, which I think means the issue doesn't have much impact: - In native_flush_tlb_multi() for checking if lazy TLB CPUs need to be IPI'd to avoid issues with speculative page table walks. - In Hyper-V TLB paravirtualization, again for lazy TLB stuff. The patch "x86/mm: only invalidate final translations with INVLPGB" which is currently under review (see <https://lore.kernel.org/all/20241230175550.4046587-13-riel@surriel.com/>) would probably be making the impact of this a lot worse.
Product status
016c4d92cd16f569c6485ae62b076c1a4b779536 (git) before 618d5612ecb7bfc1c85342daafeb2b47e29e77a3
016c4d92cd16f569c6485ae62b076c1a4b779536 (git) before 556d446068f90981e5d71ca686bdaccdd545d491
016c4d92cd16f569c6485ae62b076c1a4b779536 (git) before 0a8f806ea6b5dd64b3d1f05ff774817d5f7ddbd1
016c4d92cd16f569c6485ae62b076c1a4b779536 (git) before 0708fd6bd8161871bfbadced2ca4319b84ab44fe
016c4d92cd16f569c6485ae62b076c1a4b779536 (git) before 7085895c59e4057ffae17f58990ccb630087d0d2
016c4d92cd16f569c6485ae62b076c1a4b779536 (git) before 93224deb50a8d20df3884f3672ce9f982129aa50
016c4d92cd16f569c6485ae62b076c1a4b779536 (git) before 320ac1af4c0bdb92c864dc9250d1329234820edf
016c4d92cd16f569c6485ae62b076c1a4b779536 (git) before 78d6f9a9eb2a5da6fcbd76d6191d24b0dcc321be
016c4d92cd16f569c6485ae62b076c1a4b779536 (git) before 3ef938c3503563bfc2ac15083557f880d29c2e64
4.20
Any version before 4.20
5.4.292 (semver)
5.10.236 (semver)
5.15.180 (semver)
6.1.134 (semver)
6.6.87 (semver)
6.12.23 (semver)
6.13.11 (semver)
6.14.2 (semver)
6.15 (original_commit_for_fix)
References
lists.debian.org/debian-lts-announce/2025/05/msg00045.html
lists.debian.org/debian-lts-announce/2025/05/msg00030.html
git.kernel.org/...c/618d5612ecb7bfc1c85342daafeb2b47e29e77a3
git.kernel.org/...c/556d446068f90981e5d71ca686bdaccdd545d491
git.kernel.org/...c/0a8f806ea6b5dd64b3d1f05ff774817d5f7ddbd1
git.kernel.org/...c/0708fd6bd8161871bfbadced2ca4319b84ab44fe
git.kernel.org/...c/7085895c59e4057ffae17f58990ccb630087d0d2
git.kernel.org/...c/93224deb50a8d20df3884f3672ce9f982129aa50
git.kernel.org/...c/320ac1af4c0bdb92c864dc9250d1329234820edf
git.kernel.org/...c/78d6f9a9eb2a5da6fcbd76d6191d24b0dcc321be
git.kernel.org/...c/3ef938c3503563bfc2ac15083557f880d29c2e64