ASA-2019-00156 – Linux kernel: Object fsnotify_mark refcount leak in inotify_update_existing_watch()

In the Linux kernel since commit 4d97f7d53da7dc83 ("inotify: Add flag IN_MASK_CREATE for inotify_add_watch()"), the function inotify_update_existing_watch() in fs/notify/inotify/inotify_user.c neglects to call fsnotify_put_mark() with IN_MASK_CREATE after fsnotify_find_mark(), which will cause a memory leak (aka refcount leak).