1 files changed, 4 insertions, 0 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index f940062c8d4b..9ed3a06242a0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1488,7 +1488,11 @@ munmap_back:
                  *
                  * Answer: Yes, several device drivers can do it in their
                  *         f_op->mmap method. -DaveM
+                 * Bug: If addr is changed, prev, rb_link, rb_parent should
+                 *      be updated for vma_link()
                  */
+                WARN_ON_ONCE(addr != vma->vm_start);
+
                 addr = vma->vm_start;
                 pgoff = vma->vm_pgoff;
                 vm_flags = vma->vm_flags;