diff options
| author | Vlastimil Babka <vbabka@suse.cz> | 2023-04-27 16:09:59 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-04-27 08:11:26 -0700 |
| commit | 7e7757876f258d99266e7b3c559639289a2a45fe (patch) | |
| tree | 8b93b5915d38d68e0bee67ddd8870ad7bbd55860 | |
| parent | 6e98b09da931a00bf4e0477d0fa52748bf28fcce (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.c | 2 |
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; |