From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: Re: linux-next: Tree for Jan 20 -- Kernel panic - Unable to mount root fs Date: Wed, 21 Jan 2015 17:38:10 +0000 Message-ID: <20150121173810.GP29656@ZenIV.linux.org.uk> References: <20150120165655.GA10904@kria> <20150121153910.GD22884@ulmo.nvidia.com> <20150121155407.GA18701@kria> <6942214.D1ODllqz3j@sifl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Sabrina Dubroca , Thierry Reding , Guenter Roeck , Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-audit@redhat.com, Richard Guy Briggs To: Paul Moore Return-path: Received: from zeniv.linux.org.uk ([195.92.253.2]:44220 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753496AbbAURiV (ORCPT ); Wed, 21 Jan 2015 12:38:21 -0500 Content-Disposition: inline In-Reply-To: <6942214.D1ODllqz3j@sifl> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, Jan 21, 2015 at 11:16:23AM -0500, Paul Moore wrote: > On Wednesday, January 21, 2015 04:54:07 PM Sabrina Dubroca wrote: > > 2015-01-21, 16:39:12 +0100, Thierry Reding wrote: > > > That doesn't seem to help, at least in my case. > > > > Same here. > > Okay, thanks for trying. Sorry that didn't resolve things. > > > Well, it's probably not an audit issue. I tried audit=0 on the > > commandline, and I just rebuilt a kernel with CONFIG_AUDIT=n, and it's > > still panicing. This should have fixed any audit-related issue, > > right? > > Most likely. Back to the code I go ... FWIW, I really wonder if populate_rootfs() (run ultimately from kernel_init(), by way of kernel_init_freeable(), do_basic_setup() and do_initcalls()) ends up with some side effects as far as struct filename are concerned... Note that if we _ever_ hit reuse logics there, we are going to get bogus matches asoddingplenty - *all* those sys_mkdir(), etc. are going to be with filenames in the same reused buffer. So if anything in there leaks from one call to another, we are going to have a mess on hands. Another place where that can be a problem is devtmpfs - there's a kernel thread doing actual mkdir, mknod, etc. in that abomination and if _that_ ends up accumulating aushit entries, we'll end up with interesting problems. Folks, could you print the value of audit_dummy_context() in populate_rootfs() and in drivers/base/devtmpfs.c:devtmpfsd()?