Additional info:
BUG: soft lockup - CPU#0 stuck for 23s! [kworker/u:0:6430]
Modules linked in: fuse vfat fat usb_storage ipt_MASQUERADE nf_conntrack_netbios_ns nf_conntrack_broadcast ip6table_mangle ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 iptable_nat nf_nat_ipv4 nf_nat iptable_mangle nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack rfcomm ebtable_filter bnep ebtables ip6table_filter ip6_tables be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i cxgb3 mdio libcxgbi ib_iser rdma_cm ib_addr iw_cm ib_cm ib_sa ib_mad ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi binfmt_misc coretemp kvm_intel kvm arc4 iwldvm mac80211 uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core videodev media btusb bluetooth snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel tpm_tis snd_hda_codec tpm_infineon tpm snd_hwdep snd_seq tpm_bios iwlwifi snd_seq_device snd_pcm iTCO_wdt toshiba_acpi sparse_keymap iTCO_vendor_support toshiba_bluetooth cfg80211 wmi snd_page_alloc mei lpc_ich snd_timer snd mfd_core soundcore rfkill intel_ips microcode joydev uinput crc32c_intel i915 ghash_clmulni_intel sdhci_pci sdhci i2c_algo_bit mmc_core drm_kms_helper e1000e drm i2c_core video sunrpc
CPU 0 
Pid: 6430, comm: kworker/u:0 Not tainted 3.7.2-201.fc18.x86_64 #1 TOSHIBA PORTEGE R700/Portable PC
RIP: 0010:[<ffffffff81066958>]  [<ffffffff81066958>] tasklet_kill+0x58/0x80
RSP: 0018:ffff8800367d3cb8  EFLAGS: 00000202
RAX: 0000000000000003 RBX: 00000000000000f3 RCX: 000000000000002f
RDX: 0000000000002f2f RSI: 0000000000000246 RDI: ffff8800a97ff180
RBP: ffff8800367d3cc8 R08: ffff8800a9822600 R09: ffff8800af000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000003a98
R13: ffff8800af402c00 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8800b2e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000000025812b1 CR3: 0000000001c0b000 CR4: 00000000000007f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process kworker/u:0 (pid: 6430, threadinfo ffff8800367d2000, task ffff880070a7c560)
Stack:
 ffff8800a97fc000 0000000000000296 ffff8800367d3d18 ffffffffa02d62c8
 ffff8800367d3ce8 0000000000000246 0000000000000000 ffff8800ac0c9f10
 ffff8800a97fc000 ffff8800ac0c9f40 0000000000000000 0000000000000000
Call Trace:
 [<ffffffffa02d62c8>] iwl_trans_pcie_stop_device+0x198/0x340 [iwlwifi]
 [<ffffffffa04c1e15>] iwl_down+0x225/0x330 [iwldvm]
 [<ffffffffa04c1f6f>] iwlagn_prepare_restart+0x4f/0xd0 [iwldvm]
 [<ffffffffa04c2c92>] iwl_bg_restart+0x52/0xe0 [iwldvm]
 [<ffffffff8107a487>] process_one_work+0x147/0x490
 [<ffffffffa04c2c40>] ? iwl_op_mode_dvm_start+0xb00/0xb00 [iwldvm]
 [<ffffffff8107cd1e>] worker_thread+0x15e/0x450
 [<ffffffff8107cbc0>] ? busy_worker_rebind_fn+0x110/0x110
 [<ffffffff81081c80>] kthread+0xc0/0xd0
 [<ffffffff81010000>] ? ftrace_raw_event_xen_mmu_flush_tlb_others+0x50/0xe0
 [<ffffffff81081bc0>] ? kthread_create_on_node+0x120/0x120
 [<ffffffff8163da2c>] ret_from_fork+0x7c/0xb0
 [<ffffffff81081bc0>] ? kthread_create_on_node+0x120/0x120
Code: 44 00 00 e8 4b dc 5c 00 49 8b 44 24 08 a8 01 75 f2 f0 0f ba 2b 00 19 c0 85 c0 75 e7 49 8b 44 24 08 a8 02 74 0f 66 0f 1f 44 00 00 <49> 8b 44 24 08 a8 02 75 f7 f0 80 23 fe 5b 41 5c 5d c3 48 c7 c7 

Potential duplicate: bug 879252