Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756575AbZGMRAT (ORCPT ); Mon, 13 Jul 2009 13:00:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754819AbZGMRAS (ORCPT ); Mon, 13 Jul 2009 13:00:18 -0400 Received: from www17.your-server.de ([213.133.104.17]:55554 "EHLO www17.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753636AbZGMRAQ (ORCPT ); Mon, 13 Jul 2009 13:00:16 -0400 Subject: Re: 2.6.31-rc2: BUG: unable to handle kernel NULL pointer dereference From: Thomas Meyer To: Jiri Slaby Cc: Parag Warudkar , linux-kernel@vger.kernel.org, sds@tycho.nsa.gov, jmorris@namei.org, eparis@parisplace.org In-Reply-To: <4A5A46ED.7010907@gmail.com> References: <1247410030.1095.1.camel@localhost> <4A5A46ED.7010907@gmail.com> Content-Type: text/plain Date: Mon, 13 Jul 2009 19:00:06 +0200 Message-Id: <1247504406.5437.3.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.26.2 (2.26.2-1.fc11) Content-Transfer-Encoding: 7bit X-Authenticated-Sender: thomas@m3y3r.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6190 Lines: 102 Am Sonntag, den 12.07.2009, 22:26 +0200 schrieb Jiri Slaby: > On 07/12/2009 07:30 PM, Parag Warudkar wrote: > > static void selinux_write_opts(struct seq_file *m, > > 1012 struct security_mnt_opts *opts) > > 1013 { > > 1014 int i; > > 1015 char *prefix; > > 1016 > > 1017 for (i = 0; i < opts->num_mnt_opts; i++) { > > 1018 char *has_comma; > > 1019 > > 1020 if (opts->mnt_opts[i]) > > 1021 has_comma = strchr(opts->mnt_opts[i], ','); > > ^^^^^^^^^^^^^^^^^^^^^^^^^ > > And that is a NULL pointer dereference - but we just checked for > > opts->mnt_opts[i] for not NULL. > > Note, that there is not a NULL dereference. It dereferences 0x40 which > came in as %rdi. Looks like somebody assigned garbage in there. > > Or a single bit mem error. Is memtest OK with this machine? Will schedule a memtest run. > > What warning tainted the kernel before this oops is still interesting... There seems to be no OOPS before that BUG. Does a WARNING also set the G flag? Something like that: Jul 12 16:42:34 localhost kernel: [ 6179.647004] ------------[ cut here ]------------ Jul 12 16:42:34 localhost kernel: [ 6179.647004] WARNING: at lib/kref.c:43 kref_get+0x2f/0x4c() Jul 12 16:42:34 localhost kernel: [ 6179.647004] Hardware name: MS-7250 Jul 12 16:42:34 localhost kernel: [ 6179.647004] Modules linked in: rndis_wlan floppy olympic forcedeth [last unloaded: scsi_wait_scan] Jul 12 16:42:34 localhost kernel: [ 6179.647004] Pid: 27483, comm: pm-suspend Tainted: G W 2.6.31-rc2 #79 Jul 12 16:42:34 localhost kernel: [ 6179.647004] Call Trace: Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? warn_slowpath_common+0x84/0xb2 Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? kref_get+0x2f/0x4c Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? kobject_get+0x26/0x44 Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? cpufreq_cpu_get+0x74/0xca Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? cpufreq_suspend+0x5f/0x16f Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? disable_local_APIC+0x2d/0x6d Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? sysdev_suspend+0xa7/0x28d Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? suspend_devices_and_enter+0x11c/0x1e6 Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? enter_state+0xe5/0x14c Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? state_store+0xc1/0xf6 Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? sysfs_write_file+0xe6/0x137 Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? vfs_write+0xb4/0x126 Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? sys_write+0x55/0x90 Jul 12 16:42:34 localhost kernel: [ 6179.647004] [] ? system_call_fastpath+0x16/0x1b Jul 12 16:42:34 localhost kernel: [ 6179.647004] ---[ end trace f7a4d612974b9b3e ]--- Btw this seems also to be new in 2.6.31-rc2: Jul 12 16:42:34 localhost kernel: [ 6187.256748] sd 2:0:0:0: [sdb] Starting disk Jul 12 16:42:34 localhost kernel: [ 6190.318012] Jul 12 16:42:34 localhost kernel: [ 6190.318128] floppy driver state Jul 12 16:42:34 localhost kernel: [ 6190.318244] ------------------- Jul 12 16:42:34 localhost kernel: [ 6190.320684] now=4300857616 last interrupt=4294760495 diff=6097121 last called handler=ffffffffa00263ea Jul 12 16:42:34 localhost kernel: [ 6190.320896] timeout_message=lock fdc Jul 12 16:42:34 localhost kernel: [ 6190.321018] last output bytes: Jul 12 16:42:34 localhost kernel: [ 6190.321135] f 80 4294754488 Jul 12 16:42:34 localhost kernel: [ 6190.321251] 0 90 4294754489 Jul 12 16:42:34 localhost kernel: [ 6190.321367] 1 91 4294754489 Jul 12 16:42:34 localhost kernel: [ 6190.321484] 8 81 4294754493 Jul 12 16:42:34 localhost kernel: [ 6190.321600] 4 80 4294756489 Jul 12 16:42:34 localhost kernel: [ 6190.321717] 0 90 4294756489 Jul 12 16:42:34 localhost kernel: [ 6190.321833] f 80 4294756489 Jul 12 16:42:34 localhost kernel: [ 6190.321949] 0 90 4294756489 Jul 12 16:42:34 localhost kernel: [ 6190.322073] 0 91 4294756490 Jul 12 16:42:34 localhost kernel: [ 6190.322189] 8 81 4294756494 Jul 12 16:42:34 localhost kernel: [ 6190.322305] f 80 4294758491 Jul 12 16:42:34 localhost kernel: [ 6190.322421] 0 90 4294758491 Jul 12 16:42:34 localhost kernel: [ 6190.322538] 1 91 4294758491 Jul 12 16:42:34 localhost kernel: [ 6190.322654] 8 81 4294758496 Jul 12 16:42:34 localhost kernel: [ 6190.322770] 4 80 4294760491 Jul 12 16:42:34 localhost kernel: [ 6190.322886] 0 90 4294760491 Jul 12 16:42:34 localhost kernel: [ 6190.323010] f 80 4294760491 Jul 12 16:42:34 localhost kernel: [ 6190.323126] 0 90 4294760491 Jul 12 16:42:34 localhost kernel: [ 6190.323243] 0 91 4294760491 Jul 12 16:42:34 localhost kernel: [ 6190.323359] 8 81 4294760495 Jul 12 16:42:34 localhost kernel: [ 6190.323475] last result at 4294760495 Jul 12 16:42:34 localhost kernel: [ 6190.323591] last redo_fd_request at 4296147775 Jul 12 16:42:34 localhost kernel: [ 6190.323708] 20 0 Jul 12 16:42:34 localhost kernel: [ 6190.323869] status=4e Jul 12 16:42:34 localhost kernel: [ 6190.323984] fdc_busy=1 Jul 12 16:42:34 localhost kernel: [ 6190.324107] do_floppy=ffffffffa0022263 Jul 12 16:42:34 localhost kernel: [ 6190.324224] cont=ffffffffa002d190 Jul 12 16:42:34 localhost kernel: [ 6190.324340] current_req=(null) Jul 12 16:42:34 localhost kernel: [ 6190.324456] command_status=-1 Jul 12 16:42:34 localhost kernel: [ 6190.324572] Jul 12 16:42:34 localhost kernel: [ 6190.324689] floppy0: floppy timeout called Jul 12 16:42:34 localhost kernel: [ 6190.365498] PM: resume devices took 10.626 seconds greets thomas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/