Public bug reported:
Kernel 7.0.0-27-generic panics reliably about 20-25 seconds after every boot,
as soon as dockerd restarts a container and its veth endpoint rejoins the
docker bridge network. Reproduced on 9 out of 9 boots across two days
(2026-07-04 and 2026-07-06). Kernel 6.8.0-124-generic (from 24.04, same
machine, same workload) is completely stable — we are pinned to it as a
workaround.
Panic signature (from journal; systemd-pstore captured full dmesg on
each crash):
kernel BUG at include/linux/skbuff.h:2833!
Timeline of the final seconds (identical on every occurrence):
20:53:04 kernel: br-ff13e88b70a7: port 2(veth4caa341) entered disabled state
20:53:05 dockerd: restarting container ec7df0dc... exitCode=1 restartCount=1
20:53:09 kernel: ------------[ cut here ]------------
20:53:09 kernel: kernel BUG at include/linux/skbuff.h:2833!
(journal is cut off at the BUG line — the machine freezes hard; full traces
are in the attached pstore dmesg dumps)
Steps to reproduce:
1. Ubuntu 26.04 (upgraded from 24.04), docker-ce 29.6.1 with several compose
stacks set to restart: always.
2. Boot 7.0.0-27-generic. One container exits once during startup (races its
dependencies) and dockerd restarts it.
3. The moment the restarted container's veth joins the bridge, the kernel hits
the BUG and the machine freezes (panic screen; no SSH, no disk flush).
Environment:
- Dell Latitude 3420 (Tiger Lake, Iris Xe), Ubuntu 26.04 LTS (resolute),
upgraded from 24.04 on 2026-07-04
- Uplink: iwlwifi; docker bridge networks + veth pairs; tailscale also active
- nomodeset does not help (not graphics related — with it the panic text is
simply visible instead of freezing under plymouth)
- No disk encryption, no third-party kernel modules
Workaround: pin GRUB to boot 6.8.0-124-generic — fully stable.
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-image-7.0.0-27-generic 7.0.0-27.27
ProcVersionSignature: Ubuntu 6.8.0-124.124-generic 6.8.12
Uname: Linux 6.8.0-124-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version
k6.8.0-124-generic.
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.34.0-0ubuntu2
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path',
'/dev/snd/controlC0', '/dev/snd/hwC0D0', '/dev/snd/hwC0D2',
'/dev/snd/pcmC0D5p', '/dev/snd/pcmC0D4p', '/dev/snd/pcmC0D3p',
'/dev/snd/pcmC0D31p', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p',
'/dev/snd/pcmC0D7c', '/dev/snd/pcmC0D6c', '/dev/snd/seq', '/dev/snd/timer']
failed with exit code 1:
Card0.Amixer.info: Error: [Errno 2] No such file or directory: 'amixer'
Card0.Amixer.values: Error: [Errno 2] No such file or directory: 'amixer'
CasperMD5CheckResult: pass
Date: Mon Jul 6 21:00:32 2026
InstallationDate: Installed on 2026-03-25 (103 days ago)
InstallationMedia: Ubuntu-Server 24.04.4 LTS "Noble Numbat" - Release amd64
(20260210)
MachineType: Dell Inc. Latitude 3420
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-6.8.0-124-generic
root=/dev/mapper/ubuntu--vg-ubuntu--lv ro consoleblank=30
crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
SourcePackage: linux
UpgradeStatus: Upgraded to resolute on 2026-07-04 (2 days ago)
dmi.bios.date: 09/04/2025
dmi.bios.release: 1.44
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.44.0
dmi.board.name: 0MC6DP
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias:
dmi:bvnDellInc.:bvr1.44.0:bd09/04/2025:br1.44:svnDellInc.:pnLatitude3420:pvr:rvnDellInc.:rn0MC6DP:rvrA00:cvnDellInc.:ct10:cvr:sku0A7B:
dmi.product.family: Latitude
dmi.product.name: Latitude 3420
dmi.product.sku: 0A7B
dmi.sys.vendor: Dell Inc.
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute
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https://bugs.launchpad.net/bugs/2159646
Title:
kernel BUG at include/linux/skbuff.h:2833 — 100% reproducible panic
~20s after boot when Docker restarts a container (7.0.0-27-generic)
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