From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:43417 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752260Ab2H1S4c (ORCPT ); Tue, 28 Aug 2012 14:56:32 -0400 Date: Tue, 28 Aug 2012 11:56:27 -0700 From: Jeff Layton To: Greg KH Cc: "Myklebust, Trond" , "stable@vger.kernel.org" , "linux-nfs@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] NFS: Fix Oopses in nfs_lookup_revalidate and nfs4_lookup_revalidate Message-ID: <20120828115627.46c4626e@corrin.poochiereds.net> In-Reply-To: <20120827202311.GA16556@kroah.com> References: <1345666097-14815-1-git-send-email-Trond.Myklebust@netapp.com> <20120827200949.GA4732@kroah.com> <4FA345DA4F4AE44899BD2B03EEEC2FA908F6E388@SACEXCMBX04-PRD.hq.netapp.com> <20120827202311.GA16556@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, 27 Aug 2012 13:23:11 -0700 Greg KH wrote: > On Mon, Aug 27, 2012 at 08:16:09PM +0000, Myklebust, Trond wrote: > > On Mon, 2012-08-27 at 13:09 -0700, Greg KH wrote: > > > On Wed, Aug 22, 2012 at 04:08:17PM -0400, Trond Myklebust wrote: > > > > 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. > > > > > > > > It is fixed upstream by commit 0b728e1911c (stop passing nameidata * > > > > to ->d_revalidate()) > > > > > > So this is just a nfs-only backport of the larger patch 0b728e1911c, > > > right? Should we also do this for other filesystems as well? Or just > > > backport the whole commit? > > > > The larger patch involves a VFS api change (the atomic open code) which > > has a bunch of pre- and post-requirements. I'd assume that is a too > > large change for stable. I think that the smaller per-filesystem changes > > are probably more appropriate. The list of filesystems that care are > > likely to be small. Off the top of my head, I can only think of NFS, > > CIFS, FUSE and possibly ceph. > > Ok, I'll take this one for NFS, care to break this up also for FUSE and > CIFS and send me a patch for it? > A similar problem was already fixed quite some time ago in cifs in commit f5bc1e755d, shortly after the RCU lookup code went in. -- Jeff Layton