RHEL6: kernel crash in NFS code, RIP "Bad RIP value", called from nfs_access_free_entry

Issue

• Kernel crashed with the following message

afs_pag_wait() PAG throttling triggered, pid 20961... sleeping.  sleepcnt 0
afs_pag_wait() PAG throttling triggered, pid 17272... sleeping.  sleepcnt 0
afs: byte-range locks only enforced for processes on this machine.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<(null)>] (null)
PGD bac2d4067 PUD b57545067 PMD 0 
Oops: 0010 [#1] SMP 
last sysfs file: /sys/kernel/mm/ksm/run
CPU 12 
Modules linked in: nfs lockd fscache nfs_acl auth_rpcgss sunrpc ipmi_devintf ipmi_si ipmi_msghandler cpufreq_ondemand acpi_cpufreq freq_table mperf openafs(P)(U) dmpaa(P)(U) vxspec(P)(U) vxio(P)(U) vxdmp(P)(U) vhost_net macvtap macvlan tun kvm_intel kvm sg bnx2 sr_mod cdrom cdc_ether usbnet mii microcode serio_raw i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support ioatdma dca i7core_edac edac_core shpchp ext3 jbd mbcache qla2xxx scsi_transport_fc scsi_tgt sd_mod crc_t10dif ums_cypress usb_storage mptsas mptscsih mptbase scsi_transport_sas dm_mirror dm_region_hash dm_log dm_mod [last unloaded: mptctl]

Pid: 9245, comm: java Tainted: P           ----------------   2.6.32-220.9.1.el6.x86_64 #1 IBM BladeCenter HS22 -[7870AC1]-/68Y8163
RIP: 0010:[<0000000000000000>]  [<(null)>] (null)
RSP: 0018:ffff880665b7b8c0  EFLAGS: 00010202
RAX: ffff880b8db349f8 RBX: ffff880b8db349c0 RCX: ffff88044eec5fc0
RDX: dead000000100100 RSI: ffffffffa076c0a8 RDI: ffff880b8db349c0
RBP: ffff880665b7b8d8 R08: ffff8808b4b34c58 R09: 0000000000000000
R10: ffff880028404f40 R11: 0000000000000000 R12: ffff8808b4b34c40
R13: ffff880300d05958 R14: ffff88063b191be8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff880695500000(0063) knlGS:00000000ce1ffb70
CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
CR2: 0000000000000000 CR3: 0000000bc3c5a000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process java (pid: 9245, threadinfo ffff880665b7a000, task ffff8801db850b00)
Stack:
 ffffffffa074e49d ffff8808b4b34c40 ffff8808b4b34c40 ffff880665b7b8f8
<0> ffffffffa07a93ca ffff880665b7b8f8 ffff880665b7b938 ffff880665b7b918
<0> ffffffffa07a9cc1 ffff88063b191970 ffff880300d05870 ffff880665b7b978
Call Trace:
 [<ffffffffa074e49d>] ? put_rpccred+0x13d/0x150 [sunrpc]
 [<ffffffffa07a93ca>] nfs_access_free_entry+0x1a/0x40 [nfs]
 [<ffffffffa07a9cc1>] nfs_access_free_list+0x31/0x40 [nfs]
 [<ffffffffa07a9e9e>] nfs_access_cache_shrinker+0x1ce/0x210 [nfs]
 [<ffffffff8112995a>] shrink_slab+0x12a/0x1a0
 [<ffffffff8112c004>] zone_reclaim+0x284/0x410
 [<ffffffff8112cd20>] ? isolate_pages_global+0x0/0x350
 [<ffffffff810616f5>] ? dequeue_entity+0x105/0x2e0
 [<ffffffff811225d4>] get_page_from_freelist+0x694/0x820
 [<ffffffff810098f4>] ? __switch_to+0x2d4/0x320
 [<ffffffff814ecb0e>] ? thread_return+0x4e/0x760
 [<ffffffff81123851>] __alloc_pages_nodemask+0x111/0x940
 [<ffffffff81061c95>] ? enqueue_entity+0x125/0x420
 [<ffffffff8106208b>] ? enqueue_task_fair+0xfb/0x100
 [<ffffffff81158c2a>] alloc_pages_vma+0x9a/0x150
 [<ffffffff81171b65>] do_huge_pmd_anonymous_page+0x145/0x370
 [<ffffffff8113c4da>] handle_mm_fault+0x25a/0x2b0
 [<ffffffff810a5142>] ? do_futex+0x682/0xb00
 [<ffffffff81042b79>] __do_page_fault+0x139/0x480
 [<ffffffff814f253e>] do_page_fault+0x3e/0xa0
 [<ffffffff814ef8f5>] page_fault+0x25/0x30
Code:  Bad RIP value.
RIP  [<(null)>] (null)
 RSP <ffff880665b7b8c0>
CR2: 0000000000000000