Kernel crashes, task wpa_supplicant blocked for more than 120 seconds

Bug #1694517 reported by Cerin on 2017-05-30
This bug affects 1 person
Affects Status Importance Assigned to Milestone
wpa (Ubuntu)

Bug Description

When using Gnome-Shell on Ubuntu 16.04, the Internet connection will suddenly drop off, even though the network connection icon will still indicate a connection.

Attempting to run `sudo service network-manager restart` will hang indefinitely.

Attempting to restart Gnome-Shell via alt+F2+r, will cause Gnome-Shell to hang indefinitely.

Switching to a terminal, I inspecting `dmesg` and found several messages like:

    [178443.199324] INFO: task wpa_supplicant:1708 blocked for more than 120 seconds.
    [178443.199332] Tainted: G OE 4.4.0-78-generic #99-Ubuntu
    [178443.199335] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [178443.199337] wpa_supplicant D ffff88085849ba38 0 1708 1 0x00000000
    [178443.199345] ffff88085849ba38 ffff88087f516e30 ffff88001cd2da00 ffff880853c35a00
    [178443.199350] ffff88085849c000 ffffffff81ef8184 ffff880853c35a00 00000000ffffffff
    [178443.199354] ffffffff81ef8188 ffff88085849ba50 ffffffff8183c8f5 ffffffff81ef8180
    [178443.199358] Call Trace:
    [178443.199369] [<ffffffff8183c8f5>] schedule+0x35/0x80
    [178443.199374] [<ffffffff8183cb9e>] schedule_preempt_disabled+0xe/0x10
    [178443.199378] [<ffffffff8183e7d9>] __mutex_lock_slowpath+0xb9/0x130
    [178443.199386] [<ffffffff8183e86f>] mutex_lock+0x1f/0x30
    [178443.199393] [<ffffffff817453e5>] rtnl_lock+0x15/0x20
    [178443.199422] [<ffffffffc07168eb>] nl80211_pre_doit+0xeb/0x180 [cfg80211]
    [178443.199429] [<ffffffff81769f8d>] genl_family_rcv_msg+0x1ad/0x3e0
    [178443.199435] [<ffffffff810c3b92>] ? __wake_up_common+0x52/0x90
    [178443.199441] [<ffffffff8176a1c0>] ? genl_family_rcv_msg+0x3e0/0x3e0
    [178443.199446] [<ffffffff8176a236>] genl_rcv_msg+0x76/0xb0
    [178443.199450] [<ffffffff81769734>] netlink_rcv_skb+0xa4/0xc0
    [178443.199455] [<ffffffff81769dc8>] genl_rcv+0x28/0x40
    [178443.199459] [<ffffffff8176910a>] netlink_unicast+0x18a/0x240
    [178443.199464] [<ffffffff817694bb>] netlink_sendmsg+0x2fb/0x3a0
    [178443.199470] [<ffffffff8139f671>] ? aa_sock_msg_perm+0x61/0x150
    [178443.199477] [<ffffffff81718ae8>] sock_sendmsg+0x38/0x50
    [178443.199480] [<ffffffff81719591>] ___sys_sendmsg+0x281/0x290
    [178443.199487] [<ffffffff8103ad61>] ? __fpu__restore_sig+0xa1/0x480
    [178443.199491] [<ffffffff81719ee1>] __sys_sendmsg+0x51/0x90
    [178443.199496] [<ffffffff81719f32>] SyS_sendmsg+0x12/0x20
    [178443.199501] [<ffffffff81840a32>] entry_SYSCALL_64_fastpath+0x16/0x71

I see similar errors for other programs other than wpa_supplicant, so it might not be isolated to it, but I'm not sure where else to submit this error to.

All other `sudo` commands hung, even after 15 minutes of waiting, leaving me no choice but to reboot. However, this has happened several times after a recent update, and the symptoms always manifest exactly the same. No Internet, then Gnome-Shell hangs, then all sudo commands hang.

I managed to copy my dmesg log before the reboot, which I have attached.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: wpasupplicant 2.4-0ubuntu6
ProcVersionSignature: Ubuntu 4.4.0-78.99-generic 4.4.62
Uname: Linux 4.4.0-78-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.6
Architecture: amd64
CurrentDesktop: GNOME
Date: Tue May 30 14:56:58 2017
 # This is a distribution channel descriptor
 # For more information see
InstallationDate: Installed on 2017-03-09 (81 days ago)
InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47
SourcePackage: wpa
UpgradeStatus: No upgrade log present (probably fresh install)

Cerin (chrisspen) wrote :
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