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: leozinho29_eu@xxxxxxxxxxx
Reported-by: Mike Galbraith <efault@xxxxxx>
Reported-by: Adam Borowski <kilobyte@xxxxxxxxxx>
Cc: Jérôme Glisse <jglisse@xxxxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Cc: Ross Zwisler <zwisler@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Felix Kuehling <felix.kuehling@xxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Fixes: ac46d4f3c432 ("mm/mmu_notifier: use structure for invalidate_range_start/end calls v2")
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
FWIW, I looked through all other calls to mmu_notifier_range_init() in
the patch and didn't spot any other unintentional functional changes.
mm/rmap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index 68a1a5b869a5..0454ecc29537 100644
--- 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)) {
/*
--
2.19.2
