1 files changed, 7 insertions, 0 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 5e3e09081164..c161a14b6a8f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -287,6 +287,13 @@ int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src)
         return 0;
 
  enomem_failure:
+        /*
+         * dst->anon_vma is dropped here otherwise its degree can be incorrectly
+         * decremented in unlink_anon_vmas().
+         * We can safely do this because callers of anon_vma_clone() don't care
+         * about dst->anon_vma if anon_vma_clone() failed.
+         */
+        dst->anon_vma = NULL;
         unlink_anon_vmas(dst);
         return -ENOMEM;
 }