When exit_mmap() removes vmas belonging to an exiting task, it does not
mark them as detached since they can't be reached by other tasks and they
will be freed shortly. Once we introduce vma reuse, all vmas will have to
be in detached state before they are freed to ensure vma when reused is
in a consistent state. Add missing vma_mark_detached() before freeing the
vma.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <redacted>
---
 mm/vma.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mm/vma.c b/mm/vma.c
index b9cf552e120c..93ff42ac2002 100644
--- a/mm/vma.c
+++ b/mm/vma.c

@@ -413,10 +413,12 @@ void remove_vma(struct vm_area_struct *vma, bool unreachable)
 	if (vma->vm_file)
 		fput(vma->vm_file);
 	mpol_put(vma_policy(vma));
-	if (unreachable)
+	if (unreachable) {
+		vma_mark_detached(vma);
 		__vm_area_free(vma);
-	else
+	} else {
 		vm_area_free(vma);
+	}
 }
 
 /*

-- 
2.47.1.613.gc27f4b7a9f-goog