From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938386AbdD0FEi (ORCPT ); Thu, 27 Apr 2017 01:04:38 -0400 Received: from mail-wm0-f52.google.com ([74.125.82.52]:36052 "EHLO mail-wm0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751167AbdD0FEc (ORCPT ); Thu, 27 Apr 2017 01:04:32 -0400 MIME-Version: 1.0 In-Reply-To: References: From: Cong Wang Date: Wed, 26 Apr 2017 22:04:10 -0700 Message-ID: Subject: Re: Boot regression caused by kauditd To: Paul Moore Cc: LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 26, 2017 at 2:20 PM, Paul Moore wrote: > Hi, > > Thanks for the report, this is the only one like it that I've seen. > I'm looking at the code in Linus' tree and I'm not seeing anything > obvious ... looking at the trace above it appears that the problem is > when get_net() goes to bump the refcount and the passed net pointer is > NULL; unless I'm missing something, the only way this would happen in > kauditd_thread() is if the auditd_conn.pid value is non-zero but the > auditd_conn.net pointer is NULL. > > That shouldn't happen. > > The only way I could see that even being possible is if the > sock_net(NETLINK_CB(skb).sk) call in audit_receive_msg() returned NULL > which in turned was passed as the net pointer (third parameter) in the > auditd_set() call. Once again, I don't think this should ever be > possible? Am I missing something? I don't have time to look into it yet, I think I can take a look tomorrow. > > I realize you aren't able to reproduce this reliably, but if you do, > any chance you try it with Linus' tree? I'd like to see if we can > rule out the changes in net-next (my testing doesn't typically include > net-next patches). > Will do, I tried to boot for ~6 times today to reproduce it but just saw it once. Thanks.