1 files changed, 8 insertions, 2 deletions

diff --git a/fs/file.c b/fs/file.c
index 3d2eb4c542a4..6c672ad329e9 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -664,11 +664,17 @@ static struct file *__fget(unsigned int fd, fmode_t mask)
         struct file *file;
 
         rcu_read_lock();
+loop:
         file = fcheck_files(files, fd);
         if (file) {
-                /* File object ref couldn't be taken */
-                if ((file->f_mode & mask) || !get_file_rcu(file))
+                /* File object ref couldn't be taken.
+                 * dup2() atomicity guarantee is the reason
+                 * we loop to catch the new file (or NULL pointer)
+                 */
+                if (file->f_mode & mask)
                         file = NULL;
+                else if (!get_file_rcu(file))
+                        goto loop;
         }
         rcu_read_unlock();