mm/mmu_notifier: mm/rmap.c: Fix a mmu_notifier range bug in try_to_unmap_one

The conversion to use a structure for mmu_notifier_invalidate_range_*()
unintentionally changed the usage in try_to_unmap_one() to init the
'struct mmu_notifier_range' with vma->vm_start instead of @address,
i.e. it invalidates the wrong address range.  Revert to the correct
address range.

Manifests as KVM use-after-free WARNINGs and subsequent "BUG: Bad page
state in process X" errors when reclaiming from a KVM guest due to KVM
removing the wrong pages from its own mappings.

Reported-by: [email protected]
Reported-by: Mike Galbraith <[email protected]>
Reported-and-tested-by: Adam Borowski <[email protected]>
Reviewed-by: Jérôme Glisse <[email protected]>
Reviewed-by: Pankaj gupta <[email protected]>
Cc: Christian König <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Ross Zwisler <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Radim Krčmář <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Felix Kuehling <[email protected]>
Cc: Ralph Campbell <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Andrew Morton <[email protected]>
Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2")
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/mm/rmap.c b/mm/rmap.c
index 68a1a5b869a52cef07857559cc448a2ff8396f4b..0454ecc29537ae2598415296d4f9c216610543bd 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1371,8 +1371,8 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
         * Note that the page can not be free in this function as call of
         * try_to_unmap() must hold a reference on the page.
         */
-       mmu_notifier_range_init(&range, vma->vm_mm, vma->vm_start,
-                               min(vma->vm_end, vma->vm_start +
+       mmu_notifier_range_init(&range, vma->vm_mm, address,
+                               min(vma->vm_end, address +
                                    (PAGE_SIZE << compound_order(page))));
        if (PageHuge(page)) {
                /*