Fix the following Oops in 2.5.1: 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()) Reported-by: Richard Ems <richard.ems@xxxxxxxxxxxxxxxxx> Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> --- fs/nfs/dir.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index f430057..b1f3675 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1123,7 +1123,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd) struct nfs_fattr *fattr = NULL; int error; - if (nd->flags & LOOKUP_RCU) + if (nd && (nd->flags & LOOKUP_RCU)) return -ECHILD; parent = dget_parent(dentry); @@ -1526,7 +1526,7 @@ static int nfs4_lookup_revalidate(struct dentry *dentry, struct nameidata *nd) struct inode *dir; int openflags, ret = 0; - if (nd->flags & LOOKUP_RCU) + if (nd && (nd->flags & LOOKUP_RCU)) return -ECHILD; inode = dentry->d_inode; -- 1.7.11.2 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
