RHEL6: kernel BUG at net/sunrpc/cache.c:776! and RIP cache_read

Issue

• The system causes panic with following kernel logs.

  kernel BUG at net/sunrpc/cache.c:776!
  invalid opcode: 0000 [#1] SMP
  last sysfs file: /sys/devices/pci0000:00/0000:00:03.2/0000:09:00.0/host10/target10:0:0/10:0:0:91/state
  CPU 29
  Modules linked in: nfsd nfs_acl auth_rpcgss exportfs mmfs26(U) mmfslinux(U) tracedev(U) autofs4 ib_srp(U) scsi_transport_srp scsi_tgt lockd sunrpc rdma_ucm(U) ib_ucm(U) rdma_cm(U) iw_cm(U) ib_addr(U) bonding 8021q garp stp llc ib_ipoib(U) ib_cm(U) ib_sa(U) ipv6 ib_uverbs(U) ib_umad(U) iw_nes(U) libcrc32c iw_cxgb3(U) cxgb3(U) mlx4_ib(U) ib_mthca(U) ib_mad(U) ib_core(U) dm_round_robin dm_multipath hwperf(U) knem(U) uinput microcode sg ixgbe mdio i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support ioatdma mlx4_en(U) mlx4_core(U) igb dca shpchp ext4 mbcache jbd2 sd_mod crc_t10dif sr_mod cdrom isci libsas mpt2sas scsi_transport_sas raid_class ahci wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: ipmi_msghandler]
  
  Pid: 79260, comm: rpc.mountd Not tainted 2.6.32-279.19.1.el6.x86_64 #1 SGI.COM SUMMIT/S2600GZ
  RIP: 0010:[<ffffffffa04dcd9f>]  [<ffffffffa04dcd9f>] cache_read+0x19f/0x2d0 [sunrpc]
  RSP: 0018:ffff8803ef0e7e28  EFLAGS: 00010206
  RAX: 0000000000000001 RBX: 0000000000000800 RCX: 00000000ffff9f9d
  RDX: ffff88085c476680 RSI: 0000000000000286 RDI: 0000000000000286
  RBP: ffff8803ef0e7e88 R08: 0000000000000001 R09: 0000000000000012
  R10: 0000000000000000 R11: 0000000000000400 R12: ffffffffa04eeb78
  R13: ffff88100d84bae0 R14: ffffffffa04eeb78 R15: ffffffffa04f1180
  FS:  00007fb479317740(0000) GS:ffff88085c5a0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000003c0c8abc30 CR3: 000000072e6ff000 CR4: 00000000000406e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process rpc.mountd (pid: 79260, threadinfo ffff8803ef0e6000, task ffff88080cec6040)
  Stack:
   00007fb47954b218 0000000000000034 ffffffffa04eeae0 ffff880ff99c88f0
  <d> ffff88101c271540 00007fb47a141e20 ffff8803ef0e7e78 ffff88101b6e5d80
  <d> ffff88102abfc780 00007fb47a141e20 0000000000000800 fffffffffffffffb
  Call Trace:
   [<ffffffffa04dcf0e>] cache_read_procfs+0x1e/0x20 [sunrpc]
   [<ffffffff811db54e>] proc_reg_read+0x7e/0xc0
   [<ffffffff81176cb5>] vfs_read+0xb5/0x1a0
   [<ffffffff81176df1>] sys_read+0x51/0x90
   [<ffffffff810d3a75>] ? __audit_syscall_exit+0x265/0x290
   [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b
  Code: 5d 41 5e 41 5f c9 c3 0f 1f 44 00 00 4c 89 f8 66 ff 00 66 66 90 48 8b 7d b8 e8 ce e0 00 e1 45 8b 4d 18 45 85 c9 0f 84 96 fe ff ff <0f> 0b eb fe 0f 1f 44 00 00 8b 55 c4 41 03 55 18 31 c0 41 89 55
  RIP  [<ffffffffa04dcd9f>] cache_read+0x19f/0x2d0 [sunrpc]
   RSP <ffff8803ef0e7e28>