From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757232Ab2ILGpd (ORCPT ); Wed, 12 Sep 2012 02:45:33 -0400 Received: from cantor2.suse.de ([195.135.220.15]:49217 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756225Ab2ILGpa (ORCPT ); Wed, 12 Sep 2012 02:45:30 -0400 Message-ID: <50502F7D.10307@suse.com> Date: Wed, 12 Sep 2012 12:15:17 +0530 From: Suresh Jayaraman User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120825 Thunderbird/15.0 MIME-Version: 1.0 To: Ben Hutchings Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Trond Myklebust , Richard Ems Subject: Re: [ 92/95] NFS: Fix Oopses in nfs_lookup_revalidate and nfs4_lookup_revalidate References: <20120909224203.153990066@decadent.org.uk> In-Reply-To: <20120909224203.153990066@decadent.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/10/2012 04:13 AM, Ben Hutchings wrote: > 3.2-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Trond Myklebust > > Fix the following Oops in 3.5.1: > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 > IP: [] nfs_lookup_revalidate+0x2d/0x480 [nfs] > PGD 337c63067 PUD 0 > Oops: 0000 [#1] SMP > CPU 5 > Modules linked in: nfs fscache nfsd lockd nfs_acl auth_rpcgss sunrpc af_packet binfmt_misc cpufreq_conservative cpufreq_userspace cpufreq_powersave dm_mod acpi_cpufreq mperf coretemp gpio_ich kvm_intel joydev kvm ioatdma hid_generic igb lpc_ich i7core_edac edac_core ptp serio_raw dca pcspkr i2c_i801 mfd_core sg pps_core usbhid crc32c_intel microcode button autofs4 uhci_hcd ttm drm_kms_helper drm i2c_algo_bit sysimgblt sysfillrect syscopyarea ehci_hcd usbcore usb_common scsi_dh_rdac scsi_dh_emc scsi_dh_hp_sw scsi_dh_alua scsi_dh edd fan ata_piix thermal processor thermal_sys > > Pid: 30431, comm: java Not tainted 3.5.1-2-default #1 Supermicro X8DTT/X8DTT > RIP: 0010:[] [] nfs_lookup_revalidate+0x2d/0x480 [nfs] > RSP: 0018:ffff8801b418bd38 EFLAGS: 00010292 > RAX: 00000000fffffff6 RBX: ffff88032016d800 RCX: 0000000000000020 > RDX: ffffffff00000000 RSI: 0000000000000000 RDI: ffff8801824a7b00 > RBP: ffff8801b418bdf8 R08: 7fffff0034323030 R09: fffffffff04c03ed > R10: ffff8801824a7b00 R11: 0000000000000002 R12: ffff8801824a7b00 > R13: ffff8801824a7b00 R14: 0000000000000000 R15: ffff8803201725d0 > FS: 00002b53a46cb700(0000) GS:ffff88033fc20000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000038 CR3: 000000020a426000 CR4: 00000000000007e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process java (pid: 30431, threadinfo ffff8801b418a000, task ffff8801b5d20600) > Stack: > ffff8801b418be44 ffff88032016d800 ffff8801b418bdf8 0000000000000000 > ffff8801824a7b00 ffff8801b418bdd7 ffff8803201725d0 ffffffff8116a9c0 > ffff8801b5c38dc0 0000000000000007 ffff88032016d800 0000000000000000 > Call Trace: > [] lookup_dcache+0x80/0xe0 > [] __lookup_hash+0x23/0x90 > [] lookup_one_len+0xc5/0x100 > [] nfs_sillyrename+0xe3/0x210 [nfs] > [] vfs_unlink.part.25+0x7f/0xe0 > [] do_unlinkat+0x1ac/0x1d0 > [] system_call_fastpath+0x16/0x1b > [<00002b5348b5f527>] 0x2b5348b5f526 > Code: ec 38 b8 f6 ff ff ff 4c 89 64 24 18 4c 89 74 24 28 49 89 fc 48 89 5c 24 08 48 89 6c 24 10 49 89 f6 4c 89 6c 24 20 4c 89 7c 24 30 46 38 40 0f 85 d1 00 00 00 e8 c4 c4 df e0 48 8b 58 30 49 89 > RIP [] nfs_lookup_revalidate+0x2d/0x480 [nfs] > RSP > CR2: 0000000000000038 > ---[ end trace 845113ed191985dd ]--- > > This Oops affects 3.5 kernels and older, and is due to lookup_one_len() > calling down to the dentry revalidation code with a NULL pointer > to struct nameidata. Hmm.. in this case which filesystem is calling nfs_lookup_revalidate() with NULL nd? A similar patch has already been NACKed by Trond as it could break NFS exclusive creates. The discussion thread can be found here http://www.spinics.net/lists/linux-nfs/msg20932.html Thanks Suresh