fanotify: limit number of listeners per user

fanotify currently has no limit on the number of listeners a given user can
have open.  This patch limits the total number of listeners per user to
128.  This is the same as the inotify default limit.

Signed-off-by: Eric Paris <eparis@redhat.com>

2 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 49ceed6e92b1..4366f458a86a 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -170,6 +170,7 @@ struct fsnotify_group {
 #endif /* CONFIG_FANOTIFY_ACCESS_PERMISSIONS */
                         int f_flags;
                         unsigned int max_marks;
+                        struct user_struct *user;
                 } fanotify_data;
 #endif /* CONFIG_FANOTIFY */
         };
diff --git a/include/linux/sched.h b/include/linux/sched.h
index be7adb7588e5..6f420baf37ca 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -672,6 +672,9 @@ struct user_struct {
         atomic_t inotify_watches; /* How many inotify watches does this user have? */
         atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
 #endif
+#ifdef CONFIG_FANOTIFY
+        atomic_t fanotify_listeners;
+#endif
 #ifdef CONFIG_EPOLL
         atomic_t epoll_watches; /* The number of file descriptors currently watched */
 #endif