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authorVlastimil Babka <vbabka@suse.cz>2023-04-27 16:09:59 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2023-04-27 08:11:26 -0700
commit7e7757876f258d99266e7b3c559639289a2a45fe (patch)
tree8b93b5915d38d68e0bee67ddd8870ad7bbd55860
parent6e98b09da931a00bf4e0477d0fa52748bf28fcce (diff)
mm/mremap: fix vm_pgoff in vma_merge() case 3
After upgrading build guests to v6.3, rpm started segfaulting for specific packages, which was bisected to commit 0503ea8f5ba7 ("mm/mmap: remove __vma_adjust()"). rpm is doing many mremap() operations with file mappings of its db. The problem is that in vma_merge() case 3 (we merge with the next vma, expanding it downwards) vm_pgoff is not adjusted as it should when vm_start changes. As a result the rpm process most likely sees data from the wrong offset of the file. Fix the vm_pgoff calculation. For case 8 this is a non-functional change as the resulting vm_pgoff is the same. Reported-and-bisected-by: Jiri Slaby <jirislaby@kernel.org> Reported-and-tested-by: Fabian Vogt <fvogt@suse.com> Link: https://bugzilla.suse.com/show_bug.cgi?id=1210903 Fixes: 0503ea8f5ba7 ("mm/mmap: remove __vma_adjust()") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/mmap.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index d5475fbf5729..eefa6f0cda28 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -978,7 +978,7 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm,
vma = next; /* case 3 */
vma_start = addr;
vma_end = next->vm_end;
- vma_pgoff = mid->vm_pgoff;
+ vma_pgoff = next->vm_pgoff - pglen;
err = 0;
if (mid != next) { /* case 8 */
remove = mid;