When inode is getting deleted and someone else holds reference to a mark
attached to the inode, we just detach the connector from the inode. In
that case fsnotify_put_mark() called from fsnotify_destroy_marks() will
decide to recalculate mask for the inode and __fsnotify_recalc_mask()
will WARN about invalid connector type:
WARNING: CPU: 1 PID: 12015 at fs/notify/mark.c:139
__fsnotify_recalc_mask+0x2d7/0x350 fs/notify/mark.c:139
Actually there's no reason to warn about detached connector in
__fsnotify_recalc_mask() so just silently skip updating the mask in such
case.
Reported-by: syzbot+c34692a51b9a6ca93540@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 3ac70bfcde81 ("fsnotify: add helper to get mask from connector")
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/notify/mark.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
I plan to merge this fix through my tree for 4.19-rc2.
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 05506d60131c..59cdb27826de 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -132,13 +132,13 @@ static void __fsnotify_recalc_mask(struct fsnotify_mark_connector *conn)
struct fsnotify_mark *mark;
assert_spin_locked(&conn->lock);
+ /* We can get detached connector here when inode is getting unlinked. */
+ if (!fsnotify_valid_obj_type(conn->type))
+ return;
hlist_for_each_entry(mark, &conn->list, obj_list) {
if (mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)
new_mask |= mark->mask;
}
- if (WARN_ON(!fsnotify_valid_obj_type(conn->type)))
- return;
-
*fsnotify_conn_mask_p(conn) = new_mask;
}
--
2.16.4
