System crashes with exception RIP : sockfs_dname/RIP : _spin_lock due to kernel modules fp_gpl.

Issue

• System crashes with following call traces in Red Hat Enterprise Linux 7:

[1708515.821679] BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
[1708515.823280] IP: [<ffffffff81510324>] sockfs_dname+0x14/0x30
[1708515.824142] PGD 0 
[1708515.824965] Oops: 0000 [#1] SMP 
[1708515.825760] Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver fp_rcfs(POE) fp_fe(POE) fp_audit(POE) fp_delegation(POE) fp_ac(POE) fp_proc(POE) fp_core(POE) fp_syscall(POE) fp_gpl(OE) dsa_filter(POE) nfsv3 nfs fscache vmw_vsock_vmci_transport vsock coretemp sg ppdev vmwgfx vmw_balloon ttm drm_kms_helper pcspkr drm vmw_vmci i2c_piix4 shpchp i2c_core parport_pc parport nfsd binfmt_misc auth_rpcgss nfs_acl lockd grace ip_tables ext4 mbcache jbd2 ata_generic pata_acpi sd_mod crc_t10dif crct10dif_generic crct10dif_pclmul crct10dif_common crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel lrw gf128mul mptsas glue_helper ablk_helper mptscsih cryptd serio_raw ata_piix mptbase vmxnet3 libata scsi_transport_sas floppy sunrpc dm_mirror dm_region_hash dm_log dm_mod
[1708515.831497] CPU: 5 PID: 46187 Comm: fp-daemon Tainted: P           OE  ------------   3.10.0-327.28.3.el7.x86_64 #1
[1708515.832572] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/21/2015
[1708515.833727] task: ffff88008f670000 ti: ffff88003f1a0000 task.ti: ffff88003f1a0000
[1708515.834350] RIP: 0010:[<ffffffff81510324>]  [<ffffffff81510324>] sockfs_dname+0x14/0x30
[1708515.834995] RSP: 0000:ffff88003f1a3d10  EFLAGS: 00010282
[1708515.835622] RAX: 0000000000000000 RBX: ffff88003f1a3d70 RCX: ffffffff818de848
[1708515.836264] RDX: 0000000000001000 RSI: ffff880091f91048 RDI: ffff8800a97b3500
[1708515.836912] RBP: ffff88003f1a3d10 R08: ffff88061a8d9d00 R09: 000000018020001b
[1708515.837557] R10: ffffea00186a3600 R11: ffffffffa045e94d R12: ffff8800a97b3500
[1708515.838247] R13: ffff88003f1a3e78 R14: ffff880003ee0048 R15: 0000000000000000
[1708515.838925] FS:  0000000000000000(0000) GS:ffff880626740000(0000) knlGS:0000000000000000
[1708515.839602] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[1708515.840293] CR2: 0000000000000040 CR3: 000000000194a000 CR4: 00000000000407e0
[1708515.841038] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[1708515.841772] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[1708515.842445] Stack:
[1708515.843118]  ffff88003f1a3d60 ffffffff811f664c 000010003f1a3e78 ffff880091f92048
[1708515.843821]  ffff88003f1a3d50 ffffffff81211301 000000005165b224 ffff880091f91048
[1708515.844958]  ffff8800a97b3500 ffff88003f1a3e78 ffff88003f1a3d98 ffffffffa0581a3a
[1708515.846197] Call Trace:
[1708515.847347]  [<ffffffff811f664c>] d_path+0x4c/0x170
[1708515.848020]  [<ffffffff81211301>] ? statfs_by_dentry+0xa1/0x140
[1708515.848714]  [<ffffffffa0581a3a>] PK_rawVnodeGetFullPath+0x3e/0xde [fp_gpl]
[1708515.849368]  [<ffffffffa075e3ff>] __PK_os_fsFPDIDListFillUp+0x6d/0x33c [fp_core]
[1708515.850020]  [<ffffffffa0756978>] ? PK_fsPathFree+0x2c/0x2c [fp_core]
[1708515.850666]  [<ffffffffa075f4b3>] __PK_fsFPDIDSyncAll+0x53/0x1bc [fp_core]
[1708515.851319]  [<ffffffffa07569a8>] PK_workQueueDoJob+0x30/0x9c [fp_core]
[1708515.851966]  [<ffffffff810a5b2f>] kthread+0xcf/0xe0
[1708515.852588]  [<ffffffff810a5a60>] ? kthread_create_on_node+0x140/0x140
[1708515.853203]  [<ffffffff81646a98>] ret_from_fork+0x58/0x90
[1708515.853800]  [<ffffffff810a5a60>] ? kthread_create_on_node+0x140/0x140
[1708515.854430] Code: 81 48 c7 c6 40 e8 8d 81 48 89 e5 e8 17 54 cf ff 5d c3 0f 1f 44 00 00 66 66 66 66 90 55 48 8b 47 30 48 c7 c1 48 e8 8d 81 48 89 e5 <4c> 8b 40 40 31 c0 e8 51 85 ce ff 5d c3 66 66 66 66 66 66 2e 0f 
[1708515.856635] RIP  [<ffffffff81510324>] sockfs_dname+0x14/0x30
[1708515.857681]  RSP <ffff88003f1a3d10>
[1708515.858683] CR2: 0000000000000040

• System crashes with following call traces in Red Hat Enterprise Linux 6:

<1>BUG: unable to handle kernel NULL pointer dereference at 00000000000000b0
<1>IP: [<ffffffff8154be2e>] _spin_lock+0xe/0x30
<4>PGD 119ee7067 PUD 119ee6067 PMD 0
<4>Oops: 0002 [#1] SMP
<4>last sysfs file: /sys/devices/system/cpu/online
<4>CPU 0
<4>Modules linked in: nfs fscache nfsd lockd nfs_acl auth_rpcgss sunrpc exportfs autofs4 fp_rcfs(P)(U) fp_fe(P)(U) fp_audit(P)(U) fp_delegation(P)(U) fp_ac(P)(U) fp_proc(P)(U) fp_core(P)(U) fp_syscall(P)(U) fp_gpl(U) ipv6 ppdev parport_pc parport microcode vmware_balloon sg i2c_piix4 shpchp ext4 jbd2 mbcache sd_mod crc_t10dif sr_mod cdrom vmxnet3 vmw_pvscsi pata_acpi ata_generic ata_piix vmwgfx ttm drm_kms_helper drm i2c_core dm_mirror dm_region_hash dm_log dm_mod [last unloaded: mperf]
<4>
<4>Pid: 6332, comm: grep Tainted: P           -- ------------    2.6.32-642.4.2.el6.x86_64 #1 VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform
<4>RIP: 0010:[<ffffffff8154be2e>]  [<ffffffff8154be2e>] _spin_lock+0xe/0x30
<4>RSP: 0018:ffff88011e68bb68  EFLAGS: 00010286
<4>RAX: 0000000000010000 RBX: 0000000000000000 RCX: 0000000000000000
<4>RDX: ffff8807680b5ec0 RSI: ffff88082e92c1c0 RDI: 00000000000000b0
<4>RBP: ffff88011e68bb68 R08: ffff88082e7f7800 R09: ffff8807680b5ec0
<4>R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000000b0
<4>R13: ffff88032f76e540 R14: 0000000000000000 R15: 0000000000000000
<4>FS:  00007eff8b13f700(0000) GS:ffff880028200000(0000) knlGS:00000000f77a0b70
<4>CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
<4>CR2: 00000000000000b0 CR3: 000000011f40c000 CR4: 00000000000407f0
<4>DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
<4>DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
<4>Process grep (pid: 6332, threadinfo ffff88011e688000, task ffff88011e6ceab0)
<4>Stack:
<4> ffff88011e68bb88 ffffffff811a7248 ffff8807680b5ec0 ffff88082e92c1c0
<4><d> ffff88011e68bbe8 ffffffff81196d9c ffff880119ed5490 0000000000000001
<4><d> ffff88082e7f7800 ffff8807680b5ec0 ffff88011e68bbc8 ffff88082e92c1c0
<4>Call Trace:
<4> [<ffffffff811a7248>] get_write_access+0x28/0x60
<4> [<ffffffff81196d9c>] __dentry_open+0x2ac/0x380
<4> [<ffffffff81196ec2>] dentry_open+0x52/0xc0
<4> [<ffffffffa03e5aea>] PK_rawDentryOpen+0x1e/0x20 [fp_gpl]
<4> [<ffffffffa03e5bb7>] PK_rawVnodeToFile+0xcb/0x260 [fp_gpl]
<4> [<ffffffffa0319e92>] ? PK_readUnlock+0xe/0x10 [fp_core]
<4> [<ffffffffa010ab75>] PK_rcfsVnodeToFile+0x35/0x94 [fp_rcfs]
<4> [<ffffffffa010c59e>] PK_rcfsGetFile+0xce/0xfc [fp_rcfs]
<4> [<ffffffffa010c7a7>] PK_redirectCacheIoVfsPrevWrite+0x16d/0x1a2 [fp_rcfs]
<4> [<ffffffffa037630f>] PK_feVfscallIoPrevWrite+0x12b/0x27a [fp_fe]
<4> [<ffffffff8115a409>] ? handle_mm_fault+0x299/0x3d0
<4> [<ffffffffa036c9a6>] PK_feVfscallPrevOperations+0x2a/0x46 [fp_fe]
<4> [<ffffffffa031da16>] PK_vfscallHookStackPrevOperation+0xba/0x104 [fp_core]
<4> [<ffffffff81199830>] ? do_sync_write+0x0/0x140
<4> [<ffffffff81199830>] ? do_sync_write+0x0/0x140
<4> [<ffffffffa0324b48>] PK_vfscallfWrite+0xb4/0x12a [fp_core]
<4> [<ffffffffa03e4564>] ? PK_rawSpinLock+0xe/0x10 [fp_gpl]
<4> [<ffffffffa031e228>] ? PK_slabFree+0x98/0x104 [fp_core]
<4> [<ffffffff81199830>] ? do_sync_write+0x0/0x140
<4> [<ffffffffa041bb6d>] PK_vfscallStub_fWrite+0x59/0xa4 [fp_syscall]
<4> [<ffffffffa041dfb5>] PK_wrapper0x00PK_vfscallStub_fWrite+0x21/0x24 [fp_syscall]
<4> [<ffffffff81199c28>] vfs_write+0xb8/0x1a0
<4> [<ffffffff8119b13f>] ? fget_light_pos+0x3f/0x50
<4> [<ffffffff8119a761>] sys_write+0x51/0xb0
<4> [<ffffffff8100b0d2>] system_call_fastpath+0x16/0x1b
<4>Code: e5 0f 1f 44 00 00 fa 66 66 90 66 66 90 f0 81 2f 00 00 00 01 74 05 e8 62 c4 d5 ff c9 c3 55 48 89 e5 0f 1f 44 00 00 b8 00 00 01 00 <f0> 0f c1 07 0f b7 d0 c1 e8 10 39 c2 74 0e f3 90 66 66 90 66 90
<1>RIP  [<ffffffff8154be2e>] _spin_lock+0xe/0x30
<4> RSP <ffff88011e68bb68>
<4>CR2: 00000000000000b0