From: Vlastimil Babka <vbabka@xxxxxxx>
commit 7e7757876f258d99266e7b3c559639289a2a45fe upstream.
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@xxxxxxxxxx>
Reported-and-tested-by: Fabian Vogt <fvogt@xxxxxxxx>
Link: https://bugzilla.suse.com/show_bug.cgi?id=1210903
Fixes: 0503ea8f5ba7 ("mm/mmap: remove __vma_adjust()")
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -978,7 +978,7 @@ struct vm_area_struct *vma_merge(struct
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;
