fanotify: do not leak user reference on allocation failure

If fanotify_init is unable to allocate a new fsnotify group it will
return but will not drop its reference on the associated user struct.
Drop that reference on error.

Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 01fffe62a2d4..ca54957b1f61 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -692,8 +692,10 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 
         /* fsnotify_alloc_group takes a ref.  Dropped in fanotify_release */
         group = fsnotify_alloc_group(&fanotify_fsnotify_ops);
-        if (IS_ERR(group))
+        if (IS_ERR(group)) {
+                free_uid(user);
                 return PTR_ERR(group);
+        }
 
         group->fanotify_data.user = user;
         atomic_inc(&user->fanotify_listeners);