Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755784AbdDMSeY (ORCPT ); Thu, 13 Apr 2017 14:34:24 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48132 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755205AbdDMSeT (ORCPT ); Thu, 13 Apr 2017 14:34:19 -0400 Date: Thu, 13 Apr 2017 20:34:03 +0200 From: Greg KH To: Linus Torvalds Cc: Vegard Nossum , Dmitry Vyukov , Jiri Slaby , Andrew Morton , LKML , linux-serial Subject: Re: [GIT PULL] TTY/Serial driver fixes for 4.11-rc4 Message-ID: <20170413183403.GA16022@kroah.com> References: <20170326110432.GA9241@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.1 (2017-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 979 Lines: 27 On Thu, Apr 13, 2017 at 09:07:40AM -0700, Linus Torvalds wrote: > On Thu, Apr 13, 2017 at 3:50 AM, Vegard Nossum wrote: > > > > I've bisected a syzkaller crash down to this commit > > (5362544bebe85071188dd9e479b5a5040841c895). The crash is: > > > > [ 25.137552] BUG: unable to handle kernel paging request at 0000000000002280 > > [ 25.137579] IP: mutex_lock_interruptible+0xb/0x30 > > It would seem to be the > > if (mutex_lock_interruptible(&ldata->atomic_read_lock)) > > call in n_tty_read(), the offset is about right for a NULL 'ldata' > pointer (it's a big structure, it has a couple of character buffers of > size N_TTY_BUF_SIZE). > > I don't see the obvious fix, so I suspect at this point we should just > revert, as that commit seems to introduce worse problems that it is > supposed to fix. Greg? Unless Dmitry has a better idea, I will just revert it and send you the pull request in a day or so. thanks, greg k-h