Issue

• Kernel crashes in sget after updating from RHEL6.3 to RHEL6.4
• Null pointer dereference in sget() with the following backtraces:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000009
IP: [<ffffffff81183f23>] sget+0x2c3/0x480
PGD 20283b4067 PUD 201ea5d067 PMD 0 
Oops: 0000 [#1] SMP 
last sysfs file: /sys/devices/virtual/block/md1/md/level
CPU 20 
Modules linked in: autofs4 arc4 ecb nfs lockd fscache nfs_acl rpcsec_gss_krb5 auth_rpcgss sunrpc cpufreq_ondemand freq_table pcc_cpufreq ipv6 xfs exportfs ext3 jbd raid1 hpilo hpwdt tg3 microcode serio_raw sg iTCO_wdt iTCO_vendor_support ioatdma dca power_meter shpchp ext4 mbcache jbd2 raid10 sd_mod crc_t10dif sr_mod cdrom hpsa pata_acpi ata_generic ata_piix dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]

Pid: 37818, comm: java Not tainted 2.6.32-358.el6.x86_64 #1 HP ProLiant DL380p Gen8
RIP: 0010:[<ffffffff81183f23>]  [<ffffffff81183f23>] sget+0x2c3/0x480
RSP: 0018:ffff88102814ba38  EFLAGS: 00010257
RAX: 0000000000000000 RBX: ffffffffa03ea600 RCX: 0000000000000001
RDX: ffffffff00000001 RSI: 0000000000000002 RDI: ffff88101f4ad400
RBP: ffff88102814ba88 R08: ffff881021730000 R09: ffff88101d3ff000
R10: ffff8810278c1000 R11: 0000000000000000 R12: ffffffffa042d420
R13: ffff88101f4ad400 R14: ffffffffa042d450 R15: ffff88102814ba98
FS:  00007fd31d78d700(0000) GS:ffff880061780000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000009 CR3: 000000201a9fe000 CR4: 00000000000407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process java (pid: 37818, threadinfo ffff88102814a000, task ffff88101ddae080)
Stack:
 ffff88102814ba88 ffff88101f4ad470 ffffffffa03ea5b0 ffff8810278c1000
<d> ffff88101bf65fc5 ffff88102814bb58 ffff88101d3ff000 ffff88101c59fcc0
<d> ffff88101bf65fc5 0000000000000000 ffff88102814bad8 ffffffffa03eb189
Call Trace:
 [<ffffffffa03ea5b0>] ? nfs_set_super+0x0/0x50 [nfs]
 [<ffffffffa03eb189>] nfs4_xdev_get_sb+0xa9/0x2b0 [nfs]
 [<ffffffff8118381b>] vfs_kern_mount+0x7b/0x1b0
 [<ffffffffa03f6803>] nfs_d_automount+0x3c3/0x4d0 [nfs]
 [<ffffffffa03e2a32>] ? nfs_open_revalidate+0x52/0x2f0 [nfs]
 [<ffffffff811901a9>] follow_managed+0x219/0x2d0
 [<ffffffff811902ff>] do_lookup+0x9f/0x230
 [<ffffffffa0307f30>] ? put_rpccred+0x50/0x150 [sunrpc]
 [<ffffffff8119069d>] __link_path_walk+0x20d/0x1030
 [<ffffffff8119174a>] path_walk+0x6a/0xe0
 [<ffffffff8119191b>] do_path_lookup+0x5b/0xa0
 [<ffffffff81182460>] ? get_empty_filp+0xa0/0x180
 [<ffffffff8119285b>] do_filp_open+0xfb/0xdd0
 [<ffffffff8105e203>] ? perf_event_task_sched_out+0x33/0x80
 [<ffffffff8119f562>] ? alloc_fd+0x92/0x160
 [<ffffffff8117de79>] do_sys_open+0x69/0x140
 [<ffffffff8117df90>] sys_open+0x20/0x30
 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b
Code: 48 8b 7d c8 e8 1f fc ff ff 85 c0 0f 84 81 fd ff ff 4d 85 ed 74 5f 49 8d 7d 70 e8 69 82 f1 ff 4c 89 ef e8 21 79 09 00 49 8b 45 30 <f6> 40 09 02 74 24 49 8d bd d8 02 00 00 e8 fb 85 10 00 49 8d bd 
RIP  [<ffffffff81183f23>] sget+0x2c3/0x480
 RSP <ffff88102814ba38>
CR2: 0000000000000009