[CVE-2022-39188] mmu_gather: Force tlb-flush VM_PFNMAP vmas - #803
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[CVE-2022-39188] mmu_gather: Force tlb-flush VM_PFNMAP vmas#803TrietHoang-DL wants to merge 1 commit into
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[ Upstream commit b67fbeb ] Jann reported a race between munmap() and unmap_mapping_range(), where unmap_mapping_range() will no-op once unmap_vmas() has unlinked the VMA; however munmap() will not yet have invalidated the TLBs. Therefore unmap_mapping_range() will complete while there are still (stale) TLB entries for the specified range. Mitigate this by force flushing TLBs for VM_PFNMAP ranges. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Triet Hoang <triet.hoang@datalogic.com>
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[ Upstream commit b67fbeb ]
Jann reported a race between munmap() and unmap_mapping_range(), where unmap_mapping_range() will no-op once unmap_vmas() has unlinked the VMA; however munmap() will not yet have invalidated the TLBs.
Therefore unmap_mapping_range() will complete while there are still (stale) TLB entries for the specified range.
Mitigate this by force flushing TLBs for VM_PFNMAP ranges.
Acked-by: Will Deacon will@kernel.org