From: Vlastimil Babka vbabka@suse.cz
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@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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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;