[PATCH] mm/mremap: do not set vrm->vma NULL immediately prior to checking it

[Lorenzo Stoakes]

This seems rather unwise. If we cannot merge, extend, then we need to
recall the original VMA to see if we need to uncharge.

If we do need to, do so.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>

---
 mm/mremap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/mremap.c b/mm/mremap.c
index 0865387531ed..7db9da609c84 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -1561,11 +1561,12 @@ static unsigned long expand_vma_in_place(struct vma_remap_struct *vrm)
 	 * adjacent to the expanded vma and otherwise
 	 * compatible.
 	 */
-	vma = vrm->vma = vma_merge_extend(&vmi, vma, vrm->delta);
+	vma = vma_merge_extend(&vmi, vma, vrm->delta);
 	if (!vma) {
 		vrm_uncharge(vrm);
 		return -ENOMEM;
 	}
+	vrm->vma = vma;

 	vrm_stat_account(vrm, vrm->delta);

--
2.49.0