1 files changed, 25 insertions, 0 deletions

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 9163a6ed67d2..3fdc8a3e1134 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -25,6 +25,19 @@
 #define FANOTIFY_DEFAULT_MAX_MARKS      8192
 #define FANOTIFY_DEFAULT_MAX_LISTENERS  128
 
+/*
+ * All flags that may be specified in parameter event_f_flags of fanotify_init.
+ *
+ * Internal and external open flags are stored together in field f_flags of
+ * struct file. Only external open flags shall be allowed in event_f_flags.
+ * Internal flags like FMODE_NONOTIFY, FMODE_EXEC, FMODE_NOCMTIME shall be
+ * excluded.
+ */
+#define FANOTIFY_INIT_ALL_EVENT_F_BITS                          ( \
+                O_ACCMODE       | O_APPEND      | O_NONBLOCK    | \
+                __O_SYNC        | O_DSYNC       | O_CLOEXEC     | \
+                O_LARGEFILE     | O_NOATIME     )
+
 extern const struct fsnotify_ops fanotify_fsnotify_ops;
 
 static struct kmem_cache *fanotify_mark_cache __read_mostly;
@@ -669,6 +682,18 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
         if (flags & ~FAN_ALL_INIT_FLAGS)
                 return -EINVAL;
 
+        if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS)
+                return -EINVAL;
+
+        switch (event_f_flags & O_ACCMODE) {
+        case O_RDONLY:
+        case O_RDWR:
+        case O_WRONLY:
+                break;
+        default:
+                return -EINVAL;
+        }
+
         user = get_current_user();
         if (atomic_read(&user->fanotify_listeners) > FANOTIFY_DEFAULT_MAX_LISTENERS) {
                 free_uid(user);