Updating latest stack trace from dmesg:
[  132.216761] BUG: scheduling while atomic: nc/2911/0x00000101
[  132.216766] Modules linked in: netfilter(POF) ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle xt_tcpudp bridge stp llc ip6table_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables pci_stub vboxpci(OF) vboxnetadp(OF) vboxnetflt(OF) vboxdrv(OF) ctr ccm bnep rfcomm binfmt_misc snd_hda_codec_realtek snd_hda_codec_hdmi dell_wmi sparse_keymap rts5139(C) uvcvideo hid_multitouch videobuf2_vmalloc videobuf2_memops videobuf2_core videodev ath3k btusb bluetooth dell_laptop dcdbas snd_hda_intel snd_hda_codec snd_hwdep snd_pcm intel_rapl x86_pkg_temp_thermal snd_seq_midi intel_powerclamp coretemp snd_seq_midi_event kvm_intel arc4 kvm snd_rawmidi crct10dif_pclmul snd_page_alloc crc32_pclmul ghash_clmulni_intel ath9k aesni_intel aes_x86_64 ath9k_common ath9k_hw lrw gf128mul glue_helper ath ablk_helper cryptd mac80211 snd_seq radeon joydev serio_raw snd_seq_device snd_timer lpc_ich ttm i915 cfg80211 drm_kms_helper snd drm mei_me mei i2c_algo_bit soundcore wmi parport_pc video mac_hid ppdev lp parport hid_generic usbhid hid psmouse ahci libahci r8169 mii
[  132.217088] CPU: 1 PID: 2911 Comm: nc Tainted: PF        C O 3.13.0-32-generic #57-Ubuntu
[  132.217092] Hardware name: Dell Inc. Inspiron 5537/0FTDJN, BIOS A07 11/12/2013
[  132.217096]  ffff88025f254440 ffff88025f243a20 ffffffff8171bcb4 ffff88025f243bc0
[  132.217115]  ffff88025f243a30 ffffffff817154c1 ffff88025f243a90 ffffffff8171ff7e
[  132.217137]  ffff880085ab8000 ffff88021c8a9fd8 0000000000014440 0000000000014440
[  132.217159] Call Trace:
[  132.217166]  <IRQ>  [<ffffffff8171bcb4>] dump_stack+0x45/0x56
[  132.217197]  [<ffffffff817154c1>] __schedule_bug+0x4c/0x5a
[  132.217211]  [<ffffffff8171ff7e>] __schedule+0x69e/0x7d0
[  132.217231]  [<ffffffff817200d9>] schedule+0x29/0x70
[  132.217242]  [<ffffffff8171f329>] schedule_timeout+0x239/0x2d0
[  132.217256]  [<ffffffff81121468>] ? trace_function+0x68/0x90
[  132.217277]  [<ffffffff810817fb>] ? insert_work+0x6b/0xb0
[  132.217293]  [<ffffffff8172137e>] wait_for_completion_killable+0xbe/0x1d0
[  132.217309]  [<ffffffff8109a800>] ? wake_up_state+0x20/0x20
[  132.217327]  [<ffffffff8107fe47>] call_usermodehelper_exec+0xe7/0x150
[  132.217344]  [<ffffffff810802a3>] __request_module+0x1b3/0x2a0
[  132.217362]  [<ffffffff8111a5ad>] ? ring_buffer_unlock_commit+0x2d/0x250
[  132.217387]  [<ffffffff81385566>] textsearch_prepare+0xf6/0x170
[  132.217397]  [<ffffffff81655f30>] ? inet_del_offload+0x40/0x40
[  132.217405]  [<ffffffffa09a3043>] in_hook_func+0x43/0x150 [netfilter]
[  132.217413]  [<ffffffffa09a3005>] ? in_hook_func+0x5/0x150 [netfilter]
[  132.217422]  [<ffffffff8164faba>] nf_iterate+0x9a/0xb0
[  132.217430]  [<ffffffff81655f30>] ? inet_del_offload+0x40/0x40
[  132.217437]  [<ffffffff8164fb44>] nf_hook_slow+0x74/0x130
[  132.217443]  [<ffffffff81655f30>] ? inet_del_offload+0x40/0x40
[  132.217452]  [<ffffffff81656958>] ip_rcv+0x2f8/0x3d0
[  132.217461]  [<ffffffff81620366>] __netif_receive_skb_core+0x666/0x840
[  132.217471]  [<ffffffff81620558>] __netif_receive_skb+0x18/0x60
[  132.217478]  [<ffffffff8162107e>] process_backlog+0xae/0x1a0
[  132.217487]  [<ffffffff81620942>] net_rx_action+0x152/0x250
[  132.217497]  [<ffffffff8106cafc>] __do_softirq+0xec/0x2c0
[  132.217507]  [<ffffffff8172e09c>] do_softirq_own_stack+0x1c/0x30
[  132.217510]  <EOI>  [<ffffffff8106cd75>] do_softirq+0x55/0x60
[  132.217523]  [<ffffffff8106ce04>] local_bh_enable+0x84/0x90
[  132.217529]  [<ffffffff8165a978>] ip_finish_output+0x1b8/0x3b0
[  132.217538]  [<ffffffff8165bed8>] ip_output+0x58/0x90
[  132.217545]  [<ffffffff8165b635>] ip_local_out+0x25/0x30
[  132.217551]  [<ffffffff8165c9f5>] ip_send_skb+0x15/0x50
[  132.217559]  [<ffffffff816815cf>] udp_send_skb+0x20f/0x2a0
[  132.217567]  [<ffffffff81659a60>] ? ip_copy_metadata+0x180/0x180
[  132.217573]  [<ffffffff81682676>] udp_sendmsg+0x2f6/0xa00
[  132.217580]  [<ffffffff81121468>] ? trace_function+0x68/0x90
[  132.217590]  [<ffffffff8112856f>] ? function_trace_call+0xff/0x130
[  132.217598]  [<ffffffff8172c2ff>] ? ftrace_call+0x5/0x2f
[  132.217609]  [<ffffffff8168e8f4>] inet_sendmsg+0x64/0xb0
[  132.217615]  [<ffffffff813183b5>] ? aa_revalidate_sk+0x5/0x80
[  132.217623]  [<ffffffff81310657>] ? apparmor_socket_sendmsg+0x17/0x20
[  132.217631]  [<ffffffff81606b9e>] sock_aio_write+0xfe/0x130
[  132.217638]  [<ffffffff8111a5ad>] ? ring_buffer_unlock_commit+0x2d/0x250
[  132.217645]  [<ffffffff811bc380>] ? do_sync_read+0x90/0x90
[  132.217654]  [<ffffffff8172c2ff>] ? ftrace_call+0x5/0x2f
[  132.217662]  [<ffffffff811bc3da>] do_sync_write+0x5a/0x90
[  132.217673]  [<ffffffff811bcc5d>] vfs_write+0x1ad/0x1f0
[  132.217681]  [<ffffffff811bd599>] SyS_write+0x49/0xa0
[  132.217689]  [<ffffffff8172c87f>] tracesys+0xe1/0xe6