Description of problem: My laptop running Fedora 17 randomly crashes when using wfica (Citrix Receiver / ICA Client) proprietary closed source client for accessing remote desktop server. wfica is running as a normal user, so it shouldn't be able to cause a kernel crash. Crashes seem to happen most often when I use either wlan- or 3G mobile data Internet connection. These kernel crashes happen ramdomly, often 1-2 times a week. What usually happens is that I notice the Internet connection dies, and when I check the kernel dmesg I'm seeing the traceback. At this point I'm still able to use the gnome desktop for maybe 1-5 minutes, but applications start to fail one by one, and finally everything just halts and I need to power cycle the laptop. Without wfica the system is perfectly stable. I've been running memtest86+ for 2 days without errors. Kernel crash traceback below. I've seen the crashes happening with multiple (all?) Fedora 17 Linux 3.6.x kernel versions. Version-Release number of selected component (if applicable): Fedora 17, kernel 3.6.11-5.fc17.x86_64. How reproducible: Randomly, but usually happens 1-2 times a week. Steps to Reproduce: 1. Install Fedora 17. Install f17 updates. 2. Start wfica connection. 3. If unlucky, the kernel will crash. Actual results: Linux kernel crashes with a traceback. Expected results: Kernel doesn't crash. Additional info: Laptop in question is Lenovo T430. The traceback looks the same (similar) every time: [11056.124003] BUG: soft lockup - CPU#2 stuck for 22s! [wfica:2232] [11056.124008] Modules linked in: xts gf128mul dm_crypt fuse lockd sunrpc rfcomm bnep ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 ip6table_filter xt_state nf_conntrack ip6_tables btusb bluetooth arc4 snd_hda_codec_realtek iwldvm uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core videodev cdc_acm snd_hda_intel snd_hda_codec snd_hwdep mac80211 media snd_seq snd_seq_device snd_pcm thinkpad_acpi snd_page_alloc coretemp snd_timer kvm_intel kvm e1000e iwlwifi cdc_wdm cdc_ncm usbnet mii iTCO_wdt iTCO_vendor_support mei lpc_ich snd mfd_core cfg80211 i2c_i801 soundcore rfkill microcode uinput crc32c_intel ghash_clmulni_intel sdhci_pci sdhci mmc_core wmi i915 video i2c_algo_bit drm_kms_helper drm i2c_core [11056.124078] CPU 2 [11056.124083] Pid: 2232, comm: wfica Not tainted 3.6.11-1.fc17.x86_64 #1 LENOVO 2349H2G/2349H2G [11056.124086] RIP: 0010:[<ffffffff8156d3a0>] [<ffffffff8156d3a0>] tcp_slow_start+0x70/0xa0 [11056.124097] RSP: 0018:ffff8802c384ba18 EFLAGS: 00200246 [11056.124099] RAX: 0000000000000000 RBX: ffffffff8106c05b RCX: 000000003db56a41 [11056.124102] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8802c394c600 [11056.124104] RBP: ffff8802c384ba18 R08: 000000000000050e R09: 0000000000000000 [11056.124106] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88030cd98000 [11056.124108] R13: ffff8802c394c978 R14: ffff88030cd98000 R15: 0000000000013cc0 [11056.124111] FS: 0000000000000000(0000) GS:ffff88031e280000(0063) knlGS:00000000f6314b40 [11056.124113] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b [11056.124115] CR2: 00007fbf0e912000 CR3: 00000002c3b5b000 CR4: 00000000001407e0 [11056.124117] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [11056.124120] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [11056.124122] Process wfica (pid: 2232, threadinfo ffff8802c384a000, task ffff8802c9d85c40) [11056.124124] Stack: [11056.124126] ffff8802c384ba48 ffffffff8159624b ffff8802c384ba48 0000000000000006 [11056.124131] 0000000000000004 0000000000000003 ffff8802c384bb08 ffffffff8155f5e2 [11056.124135] ffff88031e293cc0 ffff88020000050e 00000000e4434980 0000000000000000 [11056.124139] Call Trace: [11056.124148] [<ffffffff8159624b>] bictcp_cong_avoid+0x5b/0x3c0 [11056.124153] [<ffffffff8155f5e2>] tcp_ack+0x572/0x1210 [11056.124158] [<ffffffff815604fe>] tcp_rcv_established+0x27e/0x8f0 [11056.124163] [<ffffffff8156a584>] tcp_v4_do_rcv+0x1b4/0x4c0 [11056.124170] [<ffffffff81552bc7>] tcp_prequeue_process+0x67/0xb0 [11056.124174] [<ffffffff815576d7>] tcp_recvmsg+0x9d7/0xd80 [11056.124179] [<ffffffff8157cd7b>] inet_recvmsg+0x6b/0x80 [11056.124186] [<ffffffff814f9ed2>] sock_aio_read.part.10+0x142/0x170 [11056.124193] [<ffffffff8108f05c>] ? ttwu_do_wakeup+0x2c/0xf0 [11056.124197] [<ffffffff814f9f25>] sock_aio_read+0x25/0x40 [11056.124204] [<ffffffff8118fa77>] do_sync_read+0xa7/0xe0 [11056.124210] [<ffffffff8119044d>] vfs_read+0x15d/0x180 [11056.124214] [<ffffffff811904ba>] sys_read+0x4a/0x90 [11056.124220] [<ffffffff816286e6>] sysenter_dispatch+0x7/0x21 [11056.124222] Code: 01 f6 39 b7 f0 05 00 00 0f 43 c1 03 87 b8 05 00 00 31 c9 c7 87 f0 05 00 00 00 00 00 00 39 d0 89 87 b8 05 00 00 72 13 0f 1f 40 00 <29> d0 83 c1 01 39 d0 73 f7 89 87 b8 05 00 00 8b 87 bc 05 00 00
update: This is a bug in the Linux kernel tcp fast retransmit code, and the fix(es) have been posted to netdev mailinglist and already applied by David Miller.
"[PATCH] tcp: frto should not set snd_cwnd to 0": http://www.spinics.net/lists/netdev/msg225188.html "[PATCH] tcp: fix an infinite loop in tcp_slow_start()": http://www.spinics.net/lists/netdev/msg224939.html
*** This bug has been marked as a duplicate of bug 902550 ***
m17n-db-1.7.0-7.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2016-a0cb41b316
oops sorry above update is meant for bug 903272