Ubuntu

WiFi abort problem in Xubuntu 20.04.1 LTS

Asked by Matthias Kuntze

There are sporadic WiFi aborts with opening a window requesting to enter the WiFi password that is pre-filled.
The error sometimes shows very often (e.g. 10 times/minute) or seldom (only one per day).

The problem occurs in Xubuntu 20.04.1 LTS since update to kernel 5.4.0-56 (5.4.0-58 too).
With other Xubuntu versions (e.g. 18.04 LTS) or kernel 5.4.0-54 or earlier the problem did not appear. Other OS (eg W10 or div Android) do not see this problem too.

Looking in /var/log/syslog you always find the following message from wpa_supplicant (see also iwlwifi):

>>> Dec 15 13:00:17 XFC-T420s-04 wpa_supplicant[1500]: l2_packet_send - sendto: No buffer space available

As a result the connection is disconnected and a new key is requested with the pre-filled old (right) key.

Dec 15 12:52:43 XFC-T420s-04 kernel: [ 0.000000] Linux version 5.4.0-58-generic (buildd@lcy01-amd64-004) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #64-Ubuntu SMP Wed Dec 9 08:16:25 UTC 2020 (Ubuntu 5.4.0-58.64-generic 5.4.73)
...
Dec 15 13:01:04 XFC-T420s-04 kernel: [ 507.709109] wlp3s0: associated
Dec 15 13:01:04 XFC-T420s-04 wpa_supplicant[1500]: l2_packet_send - sendto: No buffer space available
Dec 15 13:01:04 XFC-T420s-04 kernel: [ 507.711321] wlp3s0: deauthenticating from 2c:91:ab:e3:01:f8 by local choice (Reason: 1=UNSPECIFIED)
Dec 15 13:01:04 XFC-T420s-04 wpa_supplicant[1500]: wlp3s0: CTRL-EVENT-DISCONNECTED bssid=2c:91:ab:e3:01:f8 reason=1 locally_generated=1
Dec 15 13:01:04 XFC-T420s-04 wpa_supplicant[1500]: wlp3s0: WPA: 4-Way Handshake failed - pre-shared key may be incorrect
Dec 15 13:01:04 XFC-T420s-04 wpa_supplicant[1500]: wlp3s0: CTRL-EVENT-SSID-TEMP-DISABLED id=0 ssid="SSID25GHZ" auth_failures=1 duration=10 reason=WRONG_KEY
Dec 15 13:01:04 XFC-T420s-04 wpa_supplicant[1500]: wlp3s0: CTRL-EVENT-REGDOM-CHANGE init=CORE type=WORLD
Dec 15 13:01:04 XFC-T420s-04 NetworkManager[1456]: <info> [1608033664.8253] device (wlp3s0): supplicant interface state: associating -> 4-way handshake
Dec 15 13:01:04 XFC-T420s-04 NetworkManager[1456]: <warn> [1608033664.8255] sup-iface[0x5595b8054910,wlp3s0]: connection disconnected (reason -1)
Dec 15 13:01:04 XFC-T420s-04 NetworkManager[1456]: <info> [1608033664.8303] device (wlp3s0): supplicant interface state: 4-way handshake -> disconnected
Dec 15 13:01:04 XFC-T420s-04 NetworkManager[1456]: <info> [1608033664.8325] device (wlp3s0): Activation: (wifi) disconnected during association, asking for new key
Dec 15 13:01:04 XFC-T420s-04 NetworkManager[1456]: <info> [1608033664.8327] device (wlp3s0): state change: activated -> need-auth (reason 'supplicant-disconnect', sys-iface-state: 'managed')
Dec 15 13:01:04 XFC-T420s-04 NetworkManager[1456]: <info> [1608033664.8475] dhcp4 (wlp3s0): canceled DHCP transaction
Dec 15 13:01:04 XFC-T420s-04 NetworkManager[1456]: <info> [1608033664.8476] dhcp4 (wlp3s0): state changed bound -> done
Dec 15 13:01:04 XFC-T420s-04 NetworkManager[1456]: <info> [1608033664.8495] manager: NetworkManager state is now CONNECTING

The problem is only seen in the 2,4GHz net, not in the 5GHz net. It is always seen after changing the network component - e.g. after changing the WiFi channel in the router or switching between a WLAN repeater and the router MAC.
This can be found in the syslog by greping for entries like "disconnect from AP [0-9a-f:]* for new auth to [0-9a-f:]*".
The behaviour could be reproduced in the following form:
- When connected to the 2.4GHz net, force a WLAN channel switch in the router
- When connected to the 2.4GHz net connected to the repeater, switch off the repeater to force changing the network component.

Used Hardware:
- Lenovo T420s notebook (Linux XFC-T420s-04 5.4.0-58-generic #64-Ubuntu SMP Wed Dec 9 08:16:25 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux)
- Router FritzBox-7590 (FRITZ!OS: 07.21)
- Repeater FritzRepeater-2400 (FRITZ!OS: 07.21) working in a Mesh with router

Used firmware:
shiro@XFC-T420s-04:/var/log$ apt show -a linux-firmware | grep Version
Version: 1.187.6
Version: 1.187

Used network hardware:
shiro@XFC-T420s-04:/var/log$ lspci | grep Network
00:19.0 Ethernet controller: Intel Corporation 82579LM Gigabit Network Connection (Lewisville) (rev 04)
03:00.0 Network controller: Intel Corporation Centrino Advanced-N 6205 [Taylor Peak] (rev 34)

shiro@XFC-T420s-04:/var/log$ iwconfig
wlp3s0 IEEE 802.11 ESSID:"SSID25GHZ"
          Mode:Managed Frequency:2.462 GHz Access Point: 2C:91:AB:E3:01:F8
          Bit Rate=130 Mb/s Tx-Power=15 dBm
          Retry short limit:7 RTS thr:off Fragment thr:off
          Power Management:off
          Link Quality=56/70 Signal level=-54 dBm
          Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
          Tx excessive retries:0 Invalid misc:569 Missed beacon:0

lo no wireless extensions.

enp0s25 no wireless extensions.

wwx028037ec0200 no wireless extensions.

shiro@XFC-T420s-04:/var/log$ sudo lshw | grep iwlwifi
                Konfiguration: broadcast=yes driver=iwlwifi driverversion=5.4.0-58-generic firmware=18.168.6.1 ip=192.168.146.113 latency=0 link=yes multicast=yes wireless=IEEE 802.11

Who can help in solving this problem?
If you need additional information, please do not hesitate to ask.

Best regards.

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Revision history for this message
actionparsnip (andrew-woodhead666) said : 		#1

What is the output of:

sudo lshw -C network

Thanks

Revision history for this message
Andreas Staigmiller (andreas-iligan) said : 		#2

I have the same problem. We have a network with many access points all with the same SSID.
If I am in reach of different access points the problem occurs. If only one access point is available, there is no problem.

I am the first time posting here. So not sure how to past output from terminal correctly:

andreas@andreas:~$ sudo lshw -C network
  *-network
       Beschreibung: Ethernet interface
       Produkt: Ethernet Connection I217-LM
       Hersteller: Intel Corporation
       Physische ID: 19
       Bus-Informationen: pci@0000:00:19.0
       Logischer Name: eno1
       Version: 04
       Seriennummer: ec:f4:bb:19:87:83
       Kapazität: 1Gbit/s
       Breite: 32 bits
       Takt: 33MHz
       Fähigkeiten: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       Konfiguration: autonegotiation=on broadcast=yes driver=e1000e driverversion=3.2.6-k firmware=0.13-3 latency=0 link=no multicast=yes port=twisted pair
       Ressourcen: irq:34 memory:f7c00000-f7c1ffff memory:f7c3d000-f7c3dfff ioport:f080(Größe=32)
  *-network
       Beschreibung: Kabellose Verbindung
       Produkt: Centrino Advanced-N 6235
       Hersteller: Intel Corporation
       Physische ID: 0
       Bus-Informationen: pci@0000:03:00.0
       Logischer Name: wlp3s0
       Version: 24
       Seriennummer: c4:d9:87:70:4a:36
       Breite: 64 bits
       Takt: 33MHz
       Fähigkeiten: pm msi pciexpress bus_master cap_list ethernet physical wireless
       Konfiguration: broadcast=yes driver=iwlwifi driverversion=5.4.0-56-generic firmware=18.168.6.1 ip=192.168.221.250 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       Ressourcen: irq:36 memory:f7b00000-f7b01fff

Revision history for this message
Andreas Staigmiller (andreas-iligan) said : 		#3

I tried to boot into 5.4.0-54-generic kernel. Here it works with no problems.
Sorry my operating system is in German. I hope the terminal output makes still sense.

Revision history for this message
Andreas Staigmiller (andreas-iligan) said : 		#4

A further observation. My machine is switching back an forth between the different access points. When booted into kernel 54 it does this with out me noticing it. When in kernel 56 it asks every time for the password.

My guess is, that the system asks for the password by mistake.
I also observed that after a reboot (kernel 56). The laptop connects to the network and says its connected but I have no access (cannot ping the access point). Then I reconnect manually and the whole password thing starts again. ...

Revision history for this message
Max-Ulrich Farber (m.u.farber) said : 		#5

I have got the same problem in a Lenovo Thinkpad T530 and a Lenovo Thinkpad L520, both with Xubuntu 20.04.1 LTS and Intel hardware. The problem started since kernel 5.4.0-56; before with kernel 5.4.0-54 everything was still all right. It seems to me that the frequency of these random WIFI disconnections depends on how many other WLANs are active in the neighbourhood and available.

More information about the concerned hardware would be fine.

Revision history for this message
Matthias Kuntze (shiro-kano) said : 		#6

shiro@XFC-T420s-04:~$ sudo lshw -C network
[sudo] Passwort für shiro:
  *-network
       Beschreibung: Ethernet interface
       Produkt: 82579LM Gigabit Network Connection (Lewisville)
       Hersteller: Intel Corporation
       Physische ID: 19
       Bus-Informationen: pci@0000:00:19.0
       Logischer Name: enp0s25
       Version: 04
       Seriennummer: f0:de:f1:b0:c6:f0
       Kapazität: 1Gbit/s
       Breite: 32 bits
       Takt: 33MHz
       Fähigkeiten: pm msi cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       Konfiguration: autonegotiation=on broadcast=yes driver=e1000e driverversion=3.2.6-k firmware=0.13-3 latency=0 link=no multicast=yes port=twisted pair
       Ressourcen: irq:35 memory:f1600000-f161ffff memory:f162b000-f162bfff ioport:4080(Größe=32)
  *-network
       Beschreibung: Kabellose Verbindung
       Produkt: Centrino Advanced-N 6205 [Taylor Peak]
       Hersteller: Intel Corporation
       Physische ID: 0
       Bus-Informationen: pci@0000:03:00.0
       Logischer Name: wlp3s0
       Version: 34
       Seriennummer: 08:11:96:ec:f4:74
       Breite: 64 bits
       Takt: 33MHz
       Fähigkeiten: pm msi pciexpress bus_master cap_list ethernet physical wireless
       Konfiguration: broadcast=yes driver=iwlwifi driverversion=5.4.0-58-generic firmware=18.168.6.1 ip=192.168.146.113 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       Ressourcen: irq:38 memory:f1500000-f1501fff
  *-network DEAKTIVIERT
       Beschreibung: Ethernet interface
       Physische ID: 2
       Bus-Informationen: usb@2:1.4
       Logischer Name: wwx028037ec0200
       Seriennummer: 02:80:37:ec:02:00
       Fähigkeiten: ethernet physical
       Konfiguration: broadcast=yes driver=cdc_ncm driverversion=22-Aug-2005 firmware=Mobile Broadband Network Device link=no multicast=yes
shiro@XFC-T420s-04:~$

Revision history for this message
Max-Ulrich Farber (m.u.farber) said : 		#7

I'll answer to the question of actionparsnip: (sorry, my OS is in German too… Perhaps you will get along with this almost ununderstandable language !)

----------- on the Thinkpad L520 ----------

sudo lshw -C network
  *-network
       Beschreibung: Kabellose Verbindung
       Produkt: Centrino Wireless-N 1000 [Condor Peak]
       Hersteller: Intel Corporation
       Physische ID: 0
       Bus-Informationen: pci@0000:03:00.0
       Logischer Name: wlp3s0
       Version: 00
       Seriennummer: 74:e5:0b:4e:31:36
       Breite: 64 bits
       Takt: 33MHz
       Fähigkeiten: pm msi pciexpress bus_master cap_list ethernet physical wireless
       Konfiguration: broadcast=yes driver=iwlwifi driverversion=5.4.0-58-generic firmware=39.31.5.1 build 35138 ip=192.168.178.20 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       Ressourcen: irq:33 memory:f0500000-f0501fff
  *-network
       Beschreibung: Ethernet interface
       Produkt: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       Hersteller: Realtek Semiconductor Co., Ltd.
       Physische ID: 0
       Bus-Informationen: pci@0000:09:00.0
       Logischer Name: enp9s0
       Version: 03
       Seriennummer: 04:7d:7b:30:f5:34
       Breite: 64 bits
       Takt: 33MHz
       Fähigkeiten: pm msi pciexpress msix vpd bus_master cap_list ethernet physical
       Konfiguration: broadcast=yes driver=r8169 latency=0 multicast=yes
       Ressourcen: irq:17 ioport:3000(Größe=256) memory:f0a04000-f0a04fff memory:f0a00000-f0a03fff

---------- on the Thinkpad T530 ------------

 sudo lshw -C network
[sudo] Passwort für farber:
  *-network
       Beschreibung: Ethernet interface
       Produkt: 82579LM Gigabit Network Connection (Lewisville)
       Hersteller: Intel Corporation
       Physische ID: 19
       Bus-Informationen: pci@0000:00:19.0
       Logischer Name: enp0s25
       Version: 04
       Seriennummer: 3c:97:0e:90:d3:20
       Kapazität: 1Gbit/s
       Breite: 32 bits
       Takt: 33MHz
       Fähigkeiten: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       Konfiguration: autonegotiation=on broadcast=yes driver=e1000e driverversion=3.2.6-k firmware=0.13-3 latency=0 link=no multicast=yes port=twisted pair
       Ressourcen: irq:29 memory:f3900000-f391ffff memory:f393b000-f393bfff ioport:7080(Größe=32)
  *-network
       Beschreibung: Kabellose Verbindung
       Produkt: Centrino Advanced-N 6205 [Taylor Peak]
       Hersteller: Intel Corporation
       Physische ID: 0
       Bus-Informationen: pci@0000:03:00.0
       Logischer Name: wlp3s0
       Version: 34
       Seriennummer: 6c:88:14:33:61:9c
       Breite: 64 bits
       Takt: 33MHz
       Fähigkeiten: pm msi pciexpress bus_master cap_list ethernet physical wireless
       Konfiguration: broadcast=yes driver=iwlwifi driverversion=5.4.0-58-generic firmware=18.168.6.1 ip=192.168.178.24 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       Ressourcen: irq:33 memory:f3000000-f3001fff
  *-network DEAKTIVIERT
       Beschreibung: Ethernet interface
       Physische ID: 2
       Bus-Informationen: usb@3:4
       Logischer Name: wwan0
       Seriennummer: 5e:48:9d:1e:da:e2
       Fähigkeiten: ethernet physical
       Konfiguration: broadcast=yes driver=cdc_mbim driverversion=22-Aug-2005 firmware=CDC MBIM link=no multicast=yes

Revision history for this message
Max-Ulrich Farber (m.u.farber) said : 		#8

Does the problem depend on Intel Hardware? Did someone observe the same problem with hardware other than Intel?

Revision history for this message
actionparsnip (andrew-woodhead666) said : 		#9

Max, please create your own question rather than hijacking someone else's.

Revision history for this message
actionparsnip (andrew-woodhead666) said : 		#10

Try:

echo "options iwlwifi swcrypto=1 11n_disable=8" | sudo tee /etc/modprobe.d/iwlwifi_fix.conf > /dev/null

Reboot to test. If this doesn't help then run:

sudo rm /etc/modprobe.d/iwlwifi_fix.conf

Then reboot again to roll back the change

Revision history for this message
Matthias Kuntze (shiro-kano) said : 		#11

Test of actionparsnip's suggestion:

1.) To which MAC is NIC connected?
shiro@XFC-T420s-04:~$ grep "Dec 18 " /var/log/syslog | grep -i assoc
Dec 18 11:17:08 XFC-T420s-04 wpa_supplicant[1468]: wlp3s0: Trying to associate with 2c:91:ab:e3:01:f8 (SSID='SSID25GHZ' freq=2462 MHz)
Dec 18 11:17:08 XFC-T420s-04 NetworkManager[1429]: <info> [1608286628.7785] device (wlp3s0): supplicant interface state: authenticating -> associating
Dec 18 11:17:08 XFC-T420s-04 kernel: [ 13.684039] wlp3s0: associate with 2c:91:ab:e3:01:f8 (try 1/3)
Dec 18 11:17:08 XFC-T420s-04 kernel: [ 13.695347] wlp3s0: RX AssocResp from 2c:91:ab:e3:01:f8 (capab=0x1031 status=0 aid=2)
Dec 18 11:17:08 XFC-T420s-04 wpa_supplicant[1468]: wlp3s0: Associated with 2c:91:ab:e3:01:f8
Dec 18 11:17:08 XFC-T420s-04 kernel: [ 13.714742] wlp3s0: associated
Dec 18 11:17:08 XFC-T420s-04 NetworkManager[1429]: <info> [1608286628.8838] device (wlp3s0): supplicant interface state: associating -> 4-way handshake

--> I'm connected to 2c:91:ab:e3:01:f8 (Repeater-2400) in 2,4GHz net.

2.) Perform suggested action to create /etc/modprobe.d/iwlwifi_fix.conf
shiro@XFC-T420s-04:~$ echo "options iwlwifi swcrypto=1 11n_disable=8" | sudo tee /etc/modprobe.d/iwlwifi_fix.conf > /dev/null
shiro@XFC-T420s-04:~$ ls -og /etc/modprobe.d/iwlwifi_fix.conf
-rw-r--r-- 1 41 Dez 18 13:07 /etc/modprobe.d/iwlwifi_fix.conf
shiro@XFC-T420s-04:~$ reboot

3.) After reboot look for associated MAC
shiro@XFC-T420s-04:~/Dokumente$ grep "Dec 18 " /var/log/syslog | grep -i assoc
...
Dec 18 11:17:08 XFC-T420s-04 NetworkManager[1429]: <info> [1608286628.8838] device (wlp3s0): supplicant interface state: associating -> 4-way handshake
Dec 18 13:10:37 XFC-T420s-04 wpa_supplicant[914]: wlp3s0: Trying to associate with 2c:91:ab:e3:01:f8 (SSID='SSID25GHZ' freq=2462 MHz)
Dec 18 13:10:37 XFC-T420s-04 NetworkManager[847]: <info> [1608293437.9889] device (wlp3s0): supplicant interface state: authenticating -> associating
Dec 18 13:10:38 XFC-T420s-04 kernel: [ 10.182146] wlp3s0: associate with 2c:91:ab:e3:01:f8 (try 1/3)
Dec 18 13:10:38 XFC-T420s-04 kernel: [ 10.188555] wlp3s0: RX AssocResp from 2c:91:ab:e3:01:f8 (capab=0x1031 status=0 aid=1)
Dec 18 13:10:38 XFC-T420s-04 wpa_supplicant[914]: wlp3s0: Associated with 2c:91:ab:e3:01:f8
Dec 18 13:10:38 XFC-T420s-04 kernel: [ 10.206977] wlp3s0: associated
Dec 18 13:10:38 XFC-T420s-04 NetworkManager[847]: <info> [1608293438.0781] device (wlp3s0): supplicant interface state: associating -> 4-way handshake

--> I'm connected to 2c:91:ab:e3:01:f8 (Repeater-2400) in 2,4GHz net. OK!

4.) Now I send a reboot action to the Repeater-2400 to disconnect the link from a different computer.

--> A popup Window appears asking for the pre-filled password. I did a "xprop WM_CLASS" and got the result 'WM_CLASS(STRING) = "nm-applet", "Nm-applet"'
      shiro@XFC-T420s-04:~/Dokumente$ locate -b "\nm-applet"
      /usr/bin/nm-applet
    After getting too many popup windows I now switch to 5GHz to be able to enter this text.
    The following is a short but relevant excerpt from the grep output from syslog.

shiro@XFC-T420s-04:~/Dokumente$ grep "Dec 18 " /var/log/syslog | grep -i -e assoc -e "Linux version" -e "no buffer" -e "handshake"
...
Dec 18 13:10:38 XFC-T420s-04 NetworkManager[847]: <info> [1608293438.0781] device (wlp3s0): supplicant interface state: associating -> 4-way handshake
Dec 18 13:10:38 XFC-T420s-04 NetworkManager[847]: <info> [1608293438.1088] device (wlp3s0): supplicant interface state: 4-way handshake -> completed
Dec 18 13:22:48 XFC-T420s-04 wpa_supplicant[914]: wlp3s0: Trying to associate with 44:4e:6d:55:f9:11 (SSID='SSID25GHZ' freq=2462 MHz)
Dec 18 13:22:48 XFC-T420s-04 NetworkManager[847]: <info> [1608294168.2159] device (wlp3s0): supplicant interface state: authenticating -> associating
Dec 18 13:22:48 XFC-T420s-04 kernel: [ 740.341315] wlp3s0: associate with 44:4e:6d:55:f9:11 (try 1/3)
Dec 18 13:22:48 XFC-T420s-04 kernel: [ 740.347314] wlp3s0: RX AssocResp from 44:4e:6d:55:f9:11 (capab=0x1031 status=0 aid=2)
Dec 18 13:22:48 XFC-T420s-04 wpa_supplicant[914]: wlp3s0: Associated with 44:4e:6d:55:f9:11
Dec 18 13:22:48 XFC-T420s-04 kernel: [ 740.366154] wlp3s0: associated
Dec 18 13:22:48 XFC-T420s-04 NetworkManager[847]: <info> [1608294168.3145] device (wlp3s0): supplicant interface state: associating -> 4-way handshake
Dec 18 13:22:48 XFC-T420s-04 NetworkManager[847]: <info> [1608294168.3310] device (wlp3s0): supplicant interface state: 4-way handshake -> completed
Dec 18 13:30:53 XFC-T420s-04 wpa_supplicant[914]: wlp3s0: Trying to associate with 2c:91:ab:e3:01:f8 (SSID='SSID25GHZ' freq=2462 MHz)
Dec 18 13:30:53 XFC-T420s-04 NetworkManager[847]: <info> [1608294653.4862] device (wlp3s0): supplicant interface state: authenticating -> associating
Dec 18 13:30:53 XFC-T420s-04 kernel: [ 1225.567933] wlp3s0: associate with 2c:91:ab:e3:01:f8 (try 1/3)
Dec 18 13:30:53 XFC-T420s-04 kernel: [ 1225.574398] wlp3s0: RX ReassocResp from 2c:91:ab:e3:01:f8 (capab=0x1031 status=0 aid=2)
Dec 18 13:30:53 XFC-T420s-04 wpa_supplicant[914]: wlp3s0: Associated with 2c:91:ab:e3:01:f8
Dec 18 13:30:53 XFC-T420s-04 kernel: [ 1225.594485] wlp3s0: associated
Dec 18 13:30:53 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:30:53 XFC-T420s-04 wpa_supplicant[914]: wlp3s0: WPA: 4-Way Handshake failed - pre-shared key may be incorrect
Dec 18 13:30:53 XFC-T420s-04 NetworkManager[847]: <info> [1608294653.5670] device (wlp3s0): supplicant interface state: associating -> 4-way handshake
Dec 18 13:30:53 XFC-T420s-04 NetworkManager[847]: <info> [1608294653.5715] device (wlp3s0): supplicant interface state: 4-way handshake -> disconnected
Dec 18 13:30:53 XFC-T420s-04 NetworkManager[847]: <info> [1608294653.5724] device (wlp3s0): Activation: (wifi) disconnected during association, asking for new key
...

---> After reboot, the NIC connects to 44:4e:6d:55:f9:11 (router FritzBox-7590) because the repeater is restarting.
     Then it tries to change to 2c:91:ab:e3:01:f8 (Repeater-2400) maybe caused of better signal strength.
     As a result the "No buffer space available" error appears causing the popup window to appear asking for a new key

shiro@XFC-T420s-04:~/Dokumente$ grep "Dec 18 " /var/log/syslog | grep -i -e "Linux version" -e "no buffer"
Dec 18 11:17:04 XFC-T420s-04 kernel: [ 0.000000] Linux version 5.4.0-58-generic (buildd@lcy01-amd64-004) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #64-Ubuntu SMP Wed Dec 9 08:16:25 UTC 2020 (Ubuntu 5.4.0-58.64-generic 5.4.73)
Dec 18 13:10:33 XFC-T420s-04 kernel: [ 0.000000] Linux version 5.4.0-58-generic (buildd@lcy01-amd64-004) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #64-Ubuntu SMP Wed Dec 9 08:16:25 UTC 2020 (Ubuntu 5.4.0-58.64-generic 5.4.73)
Dec 18 13:30:53 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:31:41 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:33:59 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:34:12 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:34:50 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:35:09 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:35:37 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:38:09 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:38:26 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available
Dec 18 13:38:41 XFC-T420s-04 wpa_supplicant[914]: l2_packet_send - sendto: No buffer space available

--> As you can see in the above excerpt, I had 10 WiFi aborts (buffer failure) within 7 minutes.

5.) Result: As the problem remains, I'll roll back the changes

shiro@XFC-T420s-04:~/Dokumente$ sudo rm /etc/modprobe.d/iwlwifi_fix.conf
[sudo] Passwort für shiro:
shiro@XFC-T420s-04:~/Dokumente$ ls -og /etc/modprobe.d/iwlwifi_fix.conf
ls: Zugriff auf '/etc/modprobe.d/iwlwifi_fix.conf' nicht möglich: Datei oder Verzeichnis nicht gefunden
shiro@XFC-T420s-04:~/Dokumente$ reboot

If you need the screenshot of the popup window, let me know. I'll post it somewhere in the net and post the url so that you can have a look.

Revision history for this message
Max-Ulrich Farber (m.u.farber) said : 		#12

Sorry, I never intended to hijack the question. Since there was a demand for more information, and since I had the same problem, I thought that some information about my hardware could help. If it does not, please forget it.

Revision history for this message
Matthias Kuntze (shiro-kano) said : 		#13

I wish to add an important information:
In the past I had no WiFi aborts in the 5GHz net. This information I now have to correct.
The same error, that occurs very often in the 2,4GHz net now occurs in the 5GHz net too.
As in the 2,4GHz net about 20 SSIDs are shown, I was the only one in the 5GHz net. That has changed today because a neighbour has now enabled the 5GHz net too.
The error occurs, when my router switched from channel 36 to 52.

Revision history for this message
Launchpad Janitor (janitor) said : 		#14

This question was expired because it remained in the 'Open' state without activity for the last 15 days.