Created attachment 1000227 [details]
File: dmesg

Related NFSv4.2/KRB5 issues on the same machine

------------[ cut here ]------------
kernel BUG at fs/nfs/nfs4xdr.c:908!
invalid opcode: 0000 [#1] SMP 
Modules linked in: dm_crypt bnep bluetooth rfkill veth cts rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntra
 soundcore dcdbas crc32_pclmul crc32c_intel ghash_clmulni_intel nfsd auth_rpcgss nfs_acl lockd grace sunrpc uas usb_storage nouveau broadcom video mxm_wmi wm
CPU: 0 PID: 21051 Comm: kworker/0:2 Not tainted 3.18.9-200.fc21.x86_64 #1
Hardware name: Dell Inc. XPS 8300  /0Y2MRG, BIOS A06 10/17/2011
Workqueue: rpciod rpc_async_schedule [sunrpc]
task: ffff8801c1f59d70 ti: ffff8800cd4e4000 task.ti: ffff8800cd4e4000
RIP: 0010:[<ffffffffa066b029>]  [<ffffffffa066b029>] reserve_space.part.68+0x9/0x10 [nfsv4]
RSP: 0018:ffff8800cd4e78e8  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000a05e819c RCX: ffff880209085800
RDX: 0000000000000003 RSI: 00000000a05e81b0 RDI: ffff8800cd4e7b80
RBP: ffff8800cd4e78e8 R08: ffff88009d5b91f4 R09: ffff8800cd4e7b80
R10: ffffffffa0674720 R11: 000000008eb1e3b9 R12: 0000000000010000
R13: ffff8800cd613ba8 R14: 0000000000000000 R15: ffff8801c1fc1b50
FS:  0000000000000000(0000) GS:ffff88021f400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fefe2ec2330 CR3: 00000000972ac000 CR4: 00000000000407f0
Stack:
 ffff8800cd4e7a58 ffffffffa0673e65 0000000000000008 ffff880100000003
 ffff8800cd4e79c8 000000008139608e 0001000000000002 ffffffff81347f74
 0000000000000008 ffff8801bb42e73c ffff8800cd4e79f8 0000000000000000
Call Trace:
 [<ffffffffa0673e65>] encode_attrs+0x405/0x530 [nfsv4]
 [<ffffffff81347f74>] ? crypto_sha1_update+0xb4/0x1b0
 [<ffffffff813480e1>] ? sha1_final+0x71/0xf0
 [<ffffffffa0298b20>] ? xdr_reserve_space+0x20/0x170 [sunrpc]
 [<ffffffffa0674585>] encode_open+0x2e5/0x350 [nfsv4]
 [<ffffffffa02989e9>] ? xdr_encode_opaque+0x19/0x20 [sunrpc]
 [<ffffffffa066b05b>] ? encode_string+0x2b/0x40 [nfsv4]
 [<ffffffffa0674720>] ? nfs4_xdr_enc_open_noattr+0x130/0x130 [nfsv4]
 [<ffffffffa06747d3>] nfs4_xdr_enc_open+0xb3/0x140 [nfsv4]
 [<ffffffffa02c7aa8>] gss_wrap_req_priv.isra.8+0x88/0x310 [auth_rpcgss]
 [<ffffffffa05c438d>] ? gss_get_mic_kerberos+0x2fd/0x370 [rpcsec_gss_krb5]
 [<ffffffffa02c8840>] gss_wrap_req+0x160/0x1f0 [auth_rpcgss]
 [<ffffffffa02989e9>] ? xdr_encode_opaque+0x19/0x20 [sunrpc]
 [<ffffffffa02c8cd5>] ? gss_marshal+0x155/0x230 [auth_rpcgss]
 [<ffffffffa0674720>] ? nfs4_xdr_enc_open_noattr+0x130/0x130 [nfsv4]
 [<ffffffffa028e8b0>] rpcauth_wrap_req+0x60/0xf0 [sunrpc]
 [<ffffffffa028186b>] call_transmit+0x18b/0x2d0 [sunrpc]
 [<ffffffffa02816e0>] ? call_decode+0x8a0/0x8a0 [sunrpc]
 [<ffffffffa02816e0>] ? call_decode+0x8a0/0x8a0 [sunrpc]
 [<ffffffffa028b6e4>] __rpc_execute+0x94/0x450 [sunrpc]
 [<ffffffffa028bab5>] rpc_async_schedule+0x15/0x20 [sunrpc]
 [<ffffffff810b1a6d>] process_one_work+0x14d/0x3f0
 [<ffffffff810b23c3>] worker_thread+0x53/0x470
 [<ffffffff810b2370>] ? rescuer_thread+0x290/0x290
 [<ffffffff810b75b8>] kthread+0xd8/0xf0
 [<ffffffff810b74e0>] ? kthread_create_on_node+0x1b0/0x1b0
 [<ffffffff8176207c>] ret_from_fork+0x7c/0xb0
 [<ffffffff810b74e0>] ? kthread_create_on_node+0x1b0/0x1b0
Code: 00 00 48 c7 c7 46 ca 6a a0 e8 a4 df a2 e0 c6 05 63 dc 04 00 01 8b 03 eb d7 66 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48 89 e5 <0f> 0b 0f 1f 44 00 00
RIP  [<ffffffffa066b029>] reserve_space.part.68+0x9/0x10 [nfsv4]
 RSP <ffff8800cd4e78e8>
---[ end trace 6b46046cb7aaef35 ]---
BUG: unable to handle kernel paging request at ffffffffffffffd8
IP: [<ffffffff810b7c00>] kthread_data+0x10/0x20
PGD 1c14067 PUD 1c16067 PMD 0 
Oops: 0000 [#2] SMP 
Modules linked in: dm_crypt bnep bluetooth rfkill veth cts rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntra
 soundcore dcdbas crc32_pclmul crc32c_intel ghash_clmulni_intel nfsd auth_rpcgss nfs_acl lockd grace sunrpc uas usb_storage nouveau broadcom video mxm_wmi wm
CPU: 0 PID: 21051 Comm: kworker/0:2 Tainted: G      D        3.18.9-200.fc21.x86_64 #1
Hardware name: Dell Inc. XPS 8300  /0Y2MRG, BIOS A06 10/17/2011
task: ffff8801c1f59d70 ti: ffff8800cd4e4000 task.ti: ffff8800cd4e4000
RIP: 0010:[<ffffffff810b7c00>]  [<ffffffff810b7c00>] kthread_data+0x10/0x20
RSP: 0018:ffff8800cd4e7538  EFLAGS: 00010096
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000007
RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff8801c1f59d70
RBP: ffff8800cd4e7538 R08: ffff8801c1f59e00 R09: 0000000000000001
R10: 000000000000002f R11: ffff880036a3002f R12: ffff88021f413940
R13: ffff8801c1f5a248 R14: 0000000000000000 R15: ffff8801c1f59d70
FS:  0000000000000000(0000) GS:ffff88021f400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 00000000972ac000 CR4: 00000000000407f0
Stack:
 ffff8800cd4e7558 ffffffff810b2865 ffff8800cd4e7558 0000000000000000
 ffff8800cd4e75c8 ffffffff8175da11 ffff8801c1f59d70 0000000000013940
 ffff8800cd4e7fd8 0000000000013940 ffff8800cd4e75b8 ffff8801c1f59d70
Call Trace:
 [<ffffffff810b2865>] wq_worker_sleeping+0x15/0xa0
 [<ffffffff8175da11>] __schedule+0x6d1/0x890
 [<ffffffff8175dbf9>] schedule+0x29/0x70
 [<ffffffff8109bc07>] do_exit+0x837/0xa70
 [<ffffffff810177a0>] oops_end+0xa0/0xe0
 [<ffffffff81017c5b>] die+0x4b/0x70
 [<ffffffff8101402a>] do_trap+0xba/0x150
 [<ffffffff810144f6>] do_error_trap+0xa6/0x180
 [<ffffffffa066b029>] ? reserve_space.part.68+0x9/0x10 [nfsv4]
 [<ffffffff811bb1a1>] ? kzfree+0x31/0x40
 [<ffffffff811bb1a1>] ? kzfree+0x31/0x40
 [<ffffffff81014e60>] do_invalid_op+0x20/0x30
 [<ffffffff81763a7e>] invalid_op+0x1e/0x30
 [<ffffffffa0674720>] ? nfs4_xdr_enc_open_noattr+0x130/0x130 [nfsv4]
 [<ffffffffa066b029>] ? reserve_space.part.68+0x9/0x10 [nfsv4]
 [<ffffffffa0673e65>] encode_attrs+0x405/0x530 [nfsv4]
 [<ffffffff81347f74>] ? crypto_sha1_update+0xb4/0x1b0
 [<ffffffff813480e1>] ? sha1_final+0x71/0xf0
 [<ffffffffa0298b20>] ? xdr_reserve_space+0x20/0x170 [sunrpc]
 [<ffffffffa0674585>] encode_open+0x2e5/0x350 [nfsv4]
 [<ffffffffa02989e9>] ? xdr_encode_opaque+0x19/0x20 [sunrpc]
 [<ffffffffa066b05b>] ? encode_string+0x2b/0x40 [nfsv4]
 [<ffffffffa0674720>] ? nfs4_xdr_enc_open_noattr+0x130/0x130 [nfsv4]
 [<ffffffffa06747d3>] nfs4_xdr_enc_open+0xb3/0x140 [nfsv4]
 [<ffffffffa02c7aa8>] gss_wrap_req_priv.isra.8+0x88/0x310 [auth_rpcgss]
 [<ffffffffa05c438d>] ? gss_get_mic_kerberos+0x2fd/0x370 [rpcsec_gss_krb5]
 [<ffffffffa02c8840>] gss_wrap_req+0x160/0x1f0 [auth_rpcgss]
 [<ffffffffa02989e9>] ? xdr_encode_opaque+0x19/0x20 [sunrpc]
 [<ffffffffa02c8cd5>] ? gss_marshal+0x155/0x230 [auth_rpcgss]
 [<ffffffffa0674720>] ? nfs4_xdr_enc_open_noattr+0x130/0x130 [nfsv4]
 [<ffffffffa028e8b0>] rpcauth_wrap_req+0x60/0xf0 [sunrpc]
 [<ffffffffa028186b>] call_transmit+0x18b/0x2d0 [sunrpc]
 [<ffffffffa02816e0>] ? call_decode+0x8a0/0x8a0 [sunrpc]
 [<ffffffffa02816e0>] ? call_decode+0x8a0/0x8a0 [sunrpc]
 [<ffffffffa028b6e4>] __rpc_execute+0x94/0x450 [sunrpc]
 [<ffffffffa028bab5>] rpc_async_schedule+0x15/0x20 [sunrpc]
 [<ffffffff810b1a6d>] process_one_work+0x14d/0x3f0
 [<ffffffff810b23c3>] worker_thread+0x53/0x470
 [<ffffffff810b2370>] ? rescuer_thread+0x290/0x290
 [<ffffffff810b75b8>] kthread+0xd8/0xf0
 [<ffffffff810b74e0>] ? kthread_create_on_node+0x1b0/0x1b0
 [<ffffffff8176207c>] ret_from_fork+0x7c/0xb0
 [<ffffffff810b74e0>] ? kthread_create_on_node+0x1b0/0x1b0
Code: 00 48 89 e5 5d 48 8b 40 c8 48 c1 e8 02 83 e0 01 c3 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 48 8b 87 68 04 00 00 55 48 89 e5 <48> 8b 40 d8 5d c3 66
RIP  [<ffffffff810b7c00>] kthread_data+0x10/0x20
 RSP <ffff8800cd4e7538>
CR2: ffffffffffffffd8
---[ end trace 6b46046cb7aaef36 ]---
Fixing recursive fault but reboot is needed!
abrt-dump-journal-oops: Found oopses: 2
abrt-dump-journal-oops: Creating problem directories
Reported 2 kernel oopses to Abrt
------------[ cut here ]------------
WARNING: CPU: 1 PID: 23197 at kernel/watchdog.c:317 watchdog_overflow_callback+0x9c/0xd0()
Watchdog detected hard LOCKUP on cpu 1

Do you have any reason to suspect NFSv4.2 specifically?  (E.g., can you reliably reproduce the problem over 4.2 but not 4.1?)

Are you using krb5, krb5i, or krb5p?

(In reply to J. Bruce Fields from comment #3)
> Do you have any reason to suspect NFSv4.2 specifically?  (E.g., can you
> reliably reproduce the problem over 4.2 but not 4.1?)
> 
> Are you using krb5, krb5i, or krb5p?

I don't have any reason to suspect NFSv4.2 specifically, I was just stating the version that I am using.  I have not used < NFSv4.2 since before Fedora 20, as I wanted the support for SELinux labeling.

My NFSv4.2 server is configured as follows:
## /etc/fstab
/home           /export/home            none    bind    0 0
/srv/media      /export/media           none    bind    0 0
/srv/software   /export/software        none    bind    0 0

## /etc/exports
/export          2001:abc:def0::/56(sec=krb5p:krb5i:krb5,fsid=0,crossmnt) \
                 10.1.1.0/24(sec=krb5p:krb5i:krb5,fsid=0,crossmnt)
/export/home     2001:abc:def0::/56(sec=krb5p,rw) \
                 10.1.1.0/24(sec=krb5p,rw)
/export/media    2001:abc:def0::/56(sec=krb5p:krb5i,rw) \
                 10.1.1.0/24(sec=krb5p:krb5i,rw)
/export/software 2001:abc:def0::/56(sec=krb5p:krb5i,rw) \
                 10.1.1.0/24(sec=krb5p:krb5i,rw)

My NFSv4.2 client is configured as follows:
## /etc/fstab
a.example.com:/     /mnt/a    nfs rw,minorversion=2,x-systemd.automount   0 0
a.example.com:/home /home     nfs rw,minorversion=2       0 0
b.example.com:/koji /mnt/koji nfs ro,minorversion=2,sec=krb5i,x-systemd.automount 0 0

*********** MASS BUG UPDATE **************

We apologize for the inconvenience.  There is a large number of bugs to go through and several of them have gone stale.  Due to this, we are doing a mass bug update across all of the Fedora 21 kernel bugs.

Fedora 21 has now been rebased to 3.19.5-200.fc21.  Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel.

If you have moved on to Fedora 22, and are still experiencing this issue, please change the version to Fedora 22.

If you experience different issues, please open a new bug report for those.

Description of problem:
Nothing special happening during this crash.  Using my KDE-based desktop.  /home resides on NFSv4.2/KRB5 directory.

Version-Release number of selected component:
kernel

Additional info:
reporter:       libreport-2.3.0
cmdline:        BOOT_IMAGE=/vmlinuz-4.0.4-201.fc21.x86_64 root=UUID=cff1fb49-05fe-40f6-b403-823d818a00d1 ro rhgb quiet LANG=en_US.UTF-8
kernel:         4.0.4-201.fc21.x86_64
runlevel:       N 5
type:           Kerneloops

Truncated backtrace:
WARNING: CPU: 0 PID: 4177 at net/sunrpc/clnt.c:2170 call_decode+0x269/0x8a0 [sunrpc]()
Modules linked in: dm_crypt bnep bluetooth rfkill veth cts rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw uvcvideo videobuf2_vmalloc videobuf2_core videobuf2_memops v4l2_common videodev intel_rapl media snd_usb_audio snd_usbmidi_lib iosf_mbi snd_rawmidi x86_pkg_temp_thermal coretemp kvm_intel iTCO_wdt iTCO_vendor_support kvm snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_controller
 snd_hda_codec snd_hwdep lpc_ich mfd_core crct10dif_pclmul dcdbas snd_seq snd_seq_device snd_pcm i2c_i801 crc32_pclmul crc32c_intel snd_timer snd mei_me mei serio_raw ghash_clmulni_intel soundcore shpchp nfsd auth_rpcgss nfs_acl lockd grace sunrpc uas usb_storage nouveau broadcom video mxm_wmi wmi i2c_algo_bit drm_kms_helper ttm drm tg3 ptp pps_core
CPU: 0 PID: 4177 Comm: kworker/0:2H Not tainted 4.0.4-201.fc21.x86_64 #1
Hardware name: Dell Inc. XPS 8300  /0Y2MRG, BIOS A06 10/17/2011
Workqueue: rpciod rpc_async_schedule [sunrpc]
 0000000000000000 00000000fbe9e7d4 ffff8800aa58bcc8 ffffffff8177c808
 0000000000000000 0000000000000000 ffff8800aa58bd08 ffffffff8109d5ea
 ffff8801d7468798 ffff8800be2b6618 ffff8801fe883a00 ffff88020d5d3a00
Call Trace:
 [<ffffffff8177c808>] dump_stack+0x45/0x57
 [<ffffffff8109d5ea>] warn_slowpath_common+0x8a/0xc0
 [<ffffffffa0786db0>] ? nfs4_xdr_dec_readdir+0xf0/0xf0 [nfsv4]
 [<ffffffff8109d71a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffa027a0c9>] call_decode+0x269/0x8a0 [sunrpc]
 [<ffffffff8101e4e9>] ? read_tsc+0x9/0x10
 [<ffffffff8110c78b>] ? ktime_get+0x3b/0xb0
 [<ffffffffa0279e60>] ? call_refreshresult+0x150/0x150 [sunrpc]
 [<ffffffffa0279e60>] ? call_refreshresult+0x150/0x150 [sunrpc]
 [<ffffffffa0284fd4>] __rpc_execute+0x94/0x450 [sunrpc]
 [<ffffffff810d675c>] ? put_prev_task_fair+0x2c/0x40
 [<ffffffffa02853a5>] rpc_async_schedule+0x15/0x20 [sunrpc]
 [<ffffffff810b640c>] process_one_work+0x14c/0x400
 [<ffffffff810b6e93>] worker_thread+0x53/0x470
 [<ffffffff810b6e40>] ? rescuer_thread+0x300/0x300
 [<ffffffff810b6e40>] ? rescuer_thread+0x300/0x300
 [<ffffffff810bc0d8>] kthread+0xd8/0xf0
 [<ffffffff8177ee07>] ? schedule+0x37/0x90
 [<ffffffff810bc000>] ? kthread_create_on_node+0x1b0/0x1b0
 [<ffffffff81782e18>] ret_from_fork+0x58/0x90
 [<ffffffff810bc000>] ? kthread_create_on_node+0x1b0/0x1b0

Another sunrpc-related crash from earlier on the same machine:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000150
IP: [<ffffffff8126b0e5>] locks_get_lock_context+0x5/0xc0
PGD 0 
Oops: 0000 [#1] SMP 
Modules linked in: dm_crypt bnep bluetooth rfkill veth cts rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw uvcvideo snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic videobuf2_vmalloc snd_hda_intel snd_usb_audio videobuf2_core snd_hda_controller videobuf2_memops snd_hda_codec snd_usbmidi_lib v4l2_common snd_seq snd_hwdep videodev media snd_rawmidi intel_rapl snd_seq_device iosf_mbi iTCO_wdt iTCO_vendor_support
 x86_pkg_temp_thermal snd_pcm lpc_ich coretemp snd_timer snd mei_me mei dcdbas mfd_core kvm_intel kvm i2c_i801 shpchp serio_raw soundcore crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel nfsd auth_rpcgss nfs_acl lockd grace sunrpc uas usb_storage nouveau broadcom video mxm_wmi wmi i2c_algo_bit drm_kms_helper ttm drm tg3 ptp pps_core
CPU: 0 PID: 322 Comm: kworker/0:1H Not tainted 4.0.3-201.fc21.x86_64 #1
Hardware name: Dell Inc. XPS 8300  /0Y2MRG, BIOS A06 10/17/2011
Workqueue: rpciod rpc_async_schedule [sunrpc]
task: ffff880213964590 ti: ffff880036a98000 task.ti: ffff880036a98000
RIP: 0010:[<ffffffff8126b0e5>]  [<ffffffff8126b0e5>] locks_get_lock_context+0x5/0xc0
RSP: 0018:ffff880036a9bc10  EFLAGS: 00010246
RAX: ffff880036a9bc50 RBX: ffff8800d0db7c80 RCX: 0000000000003565
RDX: 0000000000000000 RSI: ffff8800d0db7c80 RDI: 0000000000000000
RBP: ffff880036a9bc98 R08: ffff8802075f1d10 R09: ffff8802075f1cd0
R10: ffff8802075f1d08 R11: 0000000000000000 R12: ffff8800d0db7cd8
R13: ffff880036a9bcd0 R14: 0000000000000000 R15: ffff88021f41f600
FS:  0000000000000000(0000) GS:ffff88021f400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000150 CR3: 0000000001c0b000 CR4: 00000000000407f0
Stack:
 ffffffff8126bd8c 0000000100b1242a ffff88021f41f600 ffff880036a9bc58
 ffff8802075f1c40 ffff880036a9bc58 0000000000000246 ffff8802075f1c40
 ffff880036a9bc50 ffff880036a9bc50 0000000046ad50cd ffff880036a9bcb8
Call Trace:
 [<ffffffff8126bd8c>] ? __posix_lock_file+0x3c/0x680
 [<ffffffff8126c43a>] posix_lock_file_wait+0x4a/0xf0
 [<ffffffffa0715dee>] ? nfs41_sequence_done+0x12e/0x300 [nfsv4]
 [<ffffffffa0717bbd>] do_vfs_lock+0x2d/0x30 [nfsv4]
 [<ffffffffa07191e2>] nfs4_locku_done+0x82/0x120 [nfsv4]
 [<ffffffffa02ae580>] ? rpc_destroy_wait_queue+0x20/0x20 [sunrpc]
 [<ffffffffa02ae580>] ? rpc_destroy_wait_queue+0x20/0x20 [sunrpc]
 [<ffffffffa02ae5ac>] rpc_exit_task+0x2c/0xa0 [sunrpc]
 [<ffffffffa02a3e60>] ? call_refreshresult+0x150/0x150 [sunrpc]
 [<ffffffffa02aefd4>] __rpc_execute+0x94/0x450 [sunrpc]
 [<ffffffffa02af3a5>] rpc_async_schedule+0x15/0x20 [sunrpc]
 [<ffffffff810b640c>] process_one_work+0x14c/0x400
 [<ffffffff810b6e93>] worker_thread+0x53/0x470
 [<ffffffff810b6e40>] ? rescuer_thread+0x300/0x300
 [<ffffffff810b6e40>] ? rescuer_thread+0x300/0x300
 [<ffffffff810bc0d8>] kthread+0xd8/0xf0
 [<ffffffff810bc000>] ? kthread_create_on_node+0x1b0/0x1b0
 [<ffffffff817832d8>] ret_from_fork+0x58/0x90
 [<ffffffff810bc000>] ? kthread_create_on_node+0x1b0/0x1b0
Code: 00 80 30 83 81 89 47 48 48 b8 ff ff ff ff ff ff ff 7f 48 89 87 80 00 00 00 48 89 f8 5b 41 5c 5d c3 0f 1f 44 00 00 66 66 66 66 90 <48> 8b 87 50 01 00 00 48 85 c0 74 07 c3 66 0f 1f 44 00 00 55 be 
RIP  [<ffffffff8126b0e5>] locks_get_lock_context+0x5/0xc0

Any chance to get a network capture?

(In reply to Benjamin Coddington from comment #8)
> Any chance to get a network capture?

Unfortunately no, as this has been a very intermittent problem and it's been such a while since I reported this.  I've been upgrading my systems each time a kernel update comes out in hopes something fixes it.  I'm now running F22 on my servers and clients.  If it happens again, I'll see what I can do.

This message is a reminder that Fedora 21 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 21. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as EOL if it remains open with a Fedora  'version'
of '21'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not 
able to fix it before Fedora 21 is end of life. If you would still like 
to see this bug fixed and are able to reproduce it against a later version 
of Fedora, you are encouraged  change the 'version' to a later Fedora 
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

Fedora 21 changed to end-of-life (EOL) status on 2015-12-01. Fedora 21 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of
Fedora please feel free to reopen this bug against that version. If you
are unable to reopen this bug, please file a new report against the
current release. If you experience problems, please add a comment to this
bug.

Thank you for reporting this bug and we are sorry it could not be fixed.