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: [<ffffffffa03789cd>] 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:[<ffffffffa03789cd>] [<ffffffffa03789cd>] 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:
> > [<ffffffff8116a9c0>] lookup_dcache+0x80/0xe0
> > [<ffffffff8116aa43>] __lookup_hash+0x23/0x90
> > [<ffffffff8116b4a5>] lookup_one_len+0xc5/0x100
> > [<ffffffffa03869a3>] nfs_sillyrename+0xe3/0x210 [nfs]
> > [<ffffffff8116cadf>] vfs_unlink.part.25+0x7f/0xe0
> > [<ffffffff8116f22c>] do_unlinkat+0x1ac/0x1d0
> > [<ffffffff815717b9>] 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 <f6> 46 38 40 0f 85 d1 00 00 00 e8 c4 c4 df e0 48 8b 58 30 49 89
> > RIP [<ffffffffa03789cd>] nfs_lookup_revalidate+0x2d/0x480 [nfs]
> > RSP <ffff8801b418bd38>
> > 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.
Cheers
Trond
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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