Ubuntu
network-manager-applet package

sporadic WiFi aborts with opening a window requesting to enter the WiFi password that is pre-filled (wpa_supplicant[..]: l2_packet_send - sendto: No buffer space available)

Bug #1908823 reported by Matthias Kuntze on 2020-12-20

This bug report is a duplicate of: Bug #1909494: wpa_supplicant and iwlwifi failing with "No buffer space available" since "kernel 5.4.0-56". Edit Remove

This bug affects 7 people

Affects		Status	Importance	Assigned to	Milestone
	network-manager-applet (Ubuntu)	Confirmed	Undecided	Unassigned

Bug Description

The WiFi connection is aborted and the nm_applet shows the window to enter the WLAN password. The password is pre-filled and you can click the ok button to reconnect.

The error occurs sometimes 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.

Additional asked information:
1) lsb_release -rd
  Description: Ubuntu 20.04.1 LTS
  Release: 20.04
2) apt-cache policy network-manager
network-manager:
  Installiert: 1.22.10-1ubuntu2.2
  Installationskandidat: 1.22.10-1ubuntu2.2
  Versionstabelle:
*** 1.22.10-1ubuntu2.2 500
        500 http://de.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     1.22.10-1ubuntu1 500
        500 http://de.archive.ubuntu.com/ubuntu focal/main amd64 Packages
3) What you expected to happen: WLAN switch in the background with no net abort.
4) What happened instead: Network abort, window-popup with focus to password, interrupted work.

All hardware that I know show the problem on laptops with Intel WLAN devices.

In /var/log/syslog you can find the error beginning with a

"wpa_supplicant[xxx]: l2_packet_send - sendto: No buffer space available"

entry. Some lines later you see the entry "asking for a new key".
The problem can be reproduced by forcing a WLAN reconnect. This happens, when the router changes the channel or when the wifi signal strength tends to modify the way from the computer to the router (direct connect or via a repeater or changing the repeater e.g. in a Mesh). This behaviour can be seen in the 2,4GHz and in the 5GHz net.

In the sent .apport file you'll see the switch from repeater (2c:91:..) to router (44:4e:..) at "Dec 20 14:18" as the repeater is forced to reboot to reproduce the error.
For further information you can see the discussion at https://answers.launchpad.net/ubuntu/+question/694566

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: network-manager-gnome 1.8.24-1ubuntu3
ProcVersionSignature: Ubuntu 5.4.0-58.64-generic 5.4.73
Uname: Linux 5.4.0-58-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.14
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: XFCE
Date: Sun Dec 20 14:19:27 2020
ExecutablePath: /usr/bin/nm-applet
IfupdownConfig:
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
InstallationDate: Installed on 2019-12-28 (357 days ago)
InstallationMedia: Xubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
IpRoute:
default via 192.168.146.1 dev wlp3s0 proto dhcp metric 600 linkdown
169.254.0.0/16 dev wlp3s0 scope link metric 1000 linkdown
192.168.146.0/24 dev wlp3s0 proto kernel scope link src 192.168.146.113 metric 600 linkdown
ProcEnviron:
LANGUAGE=de_DE
PATH=(custom, user)
XDG_RUNTIME_DIR=<set>
LANG=de_DE.UTF-8
SHELL=/bin/bash
SourcePackage: network-manager-applet
UpgradeStatus: Upgraded to focal on 2020-10-28 (52 days ago)
nmcli-nm:
RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
running 1.22.10 connecting started none enabled enabled enabled enabled disabled

See original description

Tags:

Revision history for this message

Matthias Kuntze (shiro-kano) wrote on 2020-12-20:

CRDA.txt Edit (454 bytes, text/plain; charset="utf-8")
Dependencies.txt Edit (8.3 KiB, text/plain; charset="utf-8")
IpAddr.txt Edit (953 bytes, text/plain; charset="utf-8")
IwConfig.txt Edit (289 bytes, text/plain; charset="utf-8")
NetDevice.enp0s25.txt Edit (906 bytes, text/plain; charset="utf-8")
NetDevice.lo.txt Edit (252 bytes, text/plain; charset="utf-8")
NetDevice.wlp3s0.txt Edit (993 bytes, text/plain; charset="utf-8")
NetDevice.wwx028037ec0200.txt Edit (1.2 KiB, text/plain; charset="utf-8")
NetworkManager.conf.txt Edit (97 bytes, text/plain; charset="utf-8")
PciNetwork.txt Edit (1.3 KiB, text/plain; charset="utf-8")
ProcCpuinfoMinimal.txt Edit (1.0 KiB, text/plain; charset="utf-8")
ProcMaps.txt Edit (83.0 KiB, text/plain; charset="utf-8")
ProcStatus.txt Edit (1.3 KiB, text/plain; charset="utf-8")
RfKill.txt Edit (197 bytes, text/plain; charset="utf-8")
WifiSyslog.txt Edit (181.7 KiB, text/plain; charset="utf-8")
XsessionErrors.txt Edit (2.8 KiB, text/plain; charset="utf-8")
nmcli-con.txt Edit (4.8 KiB, text/plain; charset="utf-8")
nmcli-dev.txt Edit (1.1 KiB, text/plain; charset="utf-8")

Revision history for this message

Klaus Bielke (k-bielke) wrote on 2020-12-21:

This BUG is intensively discussed in german forum:

https://forum.ubuntuusers.de/topic/funknetz-schluessel-werden-staendig-abgefragt

Revision history for this message

Launchpad Janitor (janitor) wrote on 2020-12-21:

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in network-manager-applet (Ubuntu):
status:	New → Confirmed

Revision history for this message

Max-Ulrich Farber (m.u.farber) wrote on 2020-12-21:

With me the problem always occurs when in a running connection the channel is changed. This may happen in a busy neighborhood, if in the Router (FritzBox 7530) the automatic channel selection (recommended) is selected. It certainly may happen too if a Repeater is in use.

If I switch of and on manually the WIFI, this procedure is treated as a new connection, and the installed password is found automatically with no request, quite as it aught to be.

Matthias Kuntze (shiro-kano) on 2020-12-21

description:	updated
summary:	sporadic WiFi aborts with opening a window requesting to enter the WiFi - password that is pre-filled + password that is pre-filled (wpa_supplicant[..]: l2_packet_send - + sendto: No buffer space available)