| Message ID | 20180820123203.29910-1-jack@suse.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fsnotify: fix false positive warning on inode delete | expand |
On Mon, Aug 20, 2018 at 3:32 PM Jan Kara <jack@suse.cz> wrote: > > 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@syzkaller.appspotmail.com > Fixes: 3ac70bfcde81 ("fsnotify: add helper to get mask from connector") > Signed-off-by: Jan Kara <jack@suse.cz> > --- > 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. > looks good. Thanks. > 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 >
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; }
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@syzkaller.appspotmail.com Fixes: 3ac70bfcde81 ("fsnotify: add helper to get mask from connector") Signed-off-by: Jan Kara <jack@suse.cz> --- 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.