1 files changed, 8 insertions, 2 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index fb65e822fc41..d73ef1f3e55d 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -304,8 +304,14 @@ void put_futex_key(int fshared, union futex_key *key)
  */
 static int fault_in_user_writeable(u32 __user *uaddr)
 {
-        int ret = get_user_pages(current, current->mm, (unsigned long)uaddr,
-                                 1, 1, 0, NULL, NULL);
+        struct mm_struct *mm = current->mm;
+        int ret;
+
+        down_read(&mm->mmap_sem);
+        ret = get_user_pages(current, mm, (unsigned long)uaddr,
+                             1, 1, 0, NULL, NULL);
+        up_read(&mm->mmap_sem);
+
         return ret < 0 ? ret : 0;
 }