From: Bart Van Assche Date: Mon, 11 Mar 2019 23:02:55 +0000 (-0700) Subject: workqueue: Only unregister a registered lockdep key X-Git-Tag: v5.1-rc2~6^2~1 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=82efcab3b9f3ef59e9713237c6e3c05c3a95c1ae;p=linux-2.6-block.git workqueue: Only unregister a registered lockdep key The recent change to prevent use after free and a memory leak introduced an unconditional call to wq_unregister_lockdep() in the error handling path. If the lockdep key had not been registered yet, then the lockdep core emits a warning. Only call wq_unregister_lockdep() if wq_register_lockdep() has been called first. Fixes: 009bb421b6ce ("workqueue, lockdep: Fix an alloc_workqueue() error path") Reported-by: syzbot+be0c198232f86389c3dd@syzkaller.appspotmail.com Signed-off-by: Bart Van Assche Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Linus Torvalds Cc: Tejun Heo Cc: Qian Cai Link: https://lkml.kernel.org/r/20190311230255.176081-1-bvanassche@acm.org --- diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 4026d1871407..ddee541ea97a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4266,7 +4266,7 @@ struct workqueue_struct *alloc_workqueue(const char *fmt, INIT_LIST_HEAD(&wq->list); if (alloc_and_link_pwqs(wq) < 0) - goto err_free_wq; + goto err_unreg_lockdep; if (wq_online && init_rescuer(wq) < 0) goto err_destroy; @@ -4292,9 +4292,10 @@ struct workqueue_struct *alloc_workqueue(const char *fmt, return wq; -err_free_wq: +err_unreg_lockdep: wq_unregister_lockdep(wq); wq_free_lockdep(wq); +err_free_wq: free_workqueue_attrs(wq->unbound_attrs); kfree(wq); return NULL;