1 files changed, 1 insertions, 0 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 6f61b7cc32e0..9bd8be1d235c 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -119,6 +119,7 @@ static void *m_start(struct seq_file *m, loff_t *pos)
         mm = mm_for_maps(priv->task);
         if (!mm)
                 return NULL;
+        down_read(&mm->mmap_sem);
 
         tail_vma = get_gate_vma(priv->task);
         priv->tail_vma = tail_vma;