On 27. 04. 23, 16:27, Greg KH wrote:
On Thu, Apr 27, 2023 at 04:09:59PM +0200, Vlastimil Babka wrote:
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
Hi, I'm sending this patch on top of v6.3 as I think it should be applied and backported to 6.3-stable rather sooner than later. This means there would be a small conflict when merging mm/mm-stable later. Alternatively it could be added to mm/mm-stable and upcoming 6.4 pull request, but then the stable backport would need adjustment. It's up to Linus and Andrew.
That's not how the stable tree works, sorry, it needs to be in Linus's tree _first_.
In upstream as: commit 7e7757876f258d99266e7b3c559639289a2a45fe Author: Vlastimil Babka vbabka@suse.cz Date: Thu Apr 27 16:09:59 2023 +0200
mm/mremap: fix vm_pgoff in vma_merge() case 3
Please queue for 6.3.1.
thanks,