Hi Dan! On Mon 02-07-18 09:05:49, Dan Carpenter wrote: > url: https://github.com/0day-ci/linux/commits/Jan-Kara/audit-Fix-various-races-when-tagging-and-untagging-mounts/20180629-043337 > > smatch warnings: > kernel/audit_tree.c:484 tag_chunk() warn: inconsistent returns 'mutex:&audit_tree_group->mark_mutex'. > Locked on: line 400 > Unlocked on: line 411 > > # https://github.com/0day-ci/linux/commit/86c9c9a738e409c85891519c17d94043b7f434d5 > git remote add linux-review https://github.com/0day-ci/linux > git remote update linux-review > git checkout 86c9c9a738e409c85891519c17d94043b7f434d5 > vim +484 kernel/audit_tree.c > > 74c3cbe33 Al Viro 2007-07-22 386 > 74c3cbe33 Al Viro 2007-07-22 387 /* the first tagged inode becomes root of tree */ > 74c3cbe33 Al Viro 2007-07-22 388 static int tag_chunk(struct inode *inode, struct audit_tree *tree) > 74c3cbe33 Al Viro 2007-07-22 389 { > e61ce8673 Eric Paris 2009-12-17 390 struct fsnotify_mark *old_entry, *chunk_entry; > 74c3cbe33 Al Viro 2007-07-22 391 struct audit_tree *owner; > 74c3cbe33 Al Viro 2007-07-22 392 struct audit_chunk *chunk, *old; > 74c3cbe33 Al Viro 2007-07-22 393 struct node *p; > 74c3cbe33 Al Viro 2007-07-22 394 int n; > 74c3cbe33 Al Viro 2007-07-22 395 > 86c9c9a73 Jan Kara 2018-06-28 396 mutex_lock(&audit_tree_group->mark_mutex); > b1362edfe Jan Kara 2016-12-21 397 old_entry = fsnotify_find_mark(&inode->i_fsnotify_marks, > b1362edfe Jan Kara 2016-12-21 398 audit_tree_group); > 28a3a7eb3 Eric Paris 2009-12-17 399 if (!old_entry) > 74c3cbe33 Al Viro 2007-07-22 400 return create_chunk(inode, tree); > ^^^^^^^^^^^^^^^^^^^^^^^^^ > Should we drop the lock before this return? No, because create_chunk() drops &audit_tree_group->mark_mutex in all the cases. It's a bit ugly to have a function entered with mutex held and release it but in this case it's somewhat difficult to avoid... Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
