The patch titled
Subject: mm/mremap: fix dup_anon_vma() in vma_merge() case 4
has been added to the -mm mm-unstable branch. Its filename is
mm-mremap-fix-dup_anon_vma-in-vma_merge-case-4.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mremap-fix-dup_anon_vma-in-vma_merge-case-4.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: mm/mremap: fix dup_anon_vma() in vma_merge() case 4
In case 4, we are shrinking 'prev' (PPPP in the comment) and expanding
'mid' (NNNN). So we need to make sure 'mid' clones the anon_vma from
'prev', if it doesn't have any. After commit 0503ea8f5ba7 ("mm/mmap:
remove __vma_adjust()") we can fail to do that due to wrong parameters for
dup_anon_vma(). The call is a no-op because res == next, adjust == mid
and mid == next. Fix it.
Link: https://lkml.kernel.org/r/ad91d62b-37eb-4b73-707a-3c45c9e16256@xxxxxxx
Fixes: 0503ea8f5ba7 ("mm/mmap: remove __vma_adjust()")
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/mmap.c~mm-mremap-fix-dup_anon_vma-in-vma_merge-case-4
+++ a/mm/mmap.c
@@ -973,7 +973,7 @@ struct vm_area_struct *vma_merge(struct
vma_end = addr;
adjust = mid;
adj_next = -(vma->vm_end - addr);
- err = dup_anon_vma(res, adjust);
+ err = dup_anon_vma(adjust, prev);
} else {
vma = next; /* case 3 */
vma_start = addr;
_
Patches currently in -mm which might be from vbabka@xxxxxxx are
mm-mremap-fix-dup_anon_vma-in-vma_merge-case-4.patch
