Public bug reported:
We operate a Linux-based cluster of edge routers within a highly dynamic
setting where BGP-advertised routes constantly evolve due to new next
hop destinations frequently appearing and disappearing. In areas
experiencing significant IPv6 traffic, we periodically face kernel soft
lockups. Upon investigation, these lockups seem to occur during the
traversal of the multipath circular linked-list, for finding the optimal
path, in the fib6_select_path function, specifically while iterating
through the siblings in the multipath linked-list. The problem typically
arises when the linked list is unexpectedly deleted (its reference count
reaches zero), leading to an infinite loop. This results in a soft
lockup that, if not resolved, triggers a system panic due to the
watchdog timer.
It's worth noting that this is a longstanding issue we've been dealing
with for about a year. Despite switching between different kernel
versions, the problem persists.
Attached please find the `.crash` report generated by `apport-cli`.
Thanks,
Omid
ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: linux-image-6.5.0-26-generic 6.5.0-26.26~22.04.1
ProcVersionSignature: Ubuntu 6.5.0-26.26~22.04.1-generic 6.5.13
Uname: Linux 6.5.0-26-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: unknown
Date: Tue Apr 23 00:00:14 2024
ProcEnviron:
TERM=xterm-256color
PATH=(custom, no user)
LANG=C.UTF-8
SHELL=/bin/bash
SourcePackage: linux-signed-hwe-6.5
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: linux-signed-hwe-6.5 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug jammy uec-images
** Attachment added: "report extracted from the core dump by `apport-cli`"
https://bugs.launchpad.net/bugs/2063495/+attachment/5770523/+files/linux-image-6.5.0-27-generic-202404231849.crash
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https://bugs.launchpad.net/bugs/2063495
Title:
Kernel soft lockup occures in `fib6_select_path` function
Status in linux-signed-hwe-6.5 package in Ubuntu:
New
Bug description:
We operate a Linux-based cluster of edge routers within a highly
dynamic setting where BGP-advertised routes constantly evolve due to
new next hop destinations frequently appearing and disappearing. In
areas experiencing significant IPv6 traffic, we periodically face
kernel soft lockups. Upon investigation, these lockups seem to occur
during the traversal of the multipath circular linked-list, for
finding the optimal path, in the fib6_select_path function,
specifically while iterating through the siblings in the multipath
linked-list. The problem typically arises when the linked list is
unexpectedly deleted (its reference count reaches zero), leading to an
infinite loop. This results in a soft lockup that, if not resolved,
triggers a system panic due to the watchdog timer.
It's worth noting that this is a longstanding issue we've been dealing
with for about a year. Despite switching between different kernel
versions, the problem persists.
Attached please find the `.crash` report generated by `apport-cli`.
Thanks,
Omid
ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: linux-image-6.5.0-26-generic 6.5.0-26.26~22.04.1
ProcVersionSignature: Ubuntu 6.5.0-26.26~22.04.1-generic 6.5.13
Uname: Linux 6.5.0-26-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: unknown
Date: Tue Apr 23 00:00:14 2024
ProcEnviron:
TERM=xterm-256color
PATH=(custom, no user)
LANG=C.UTF-8
SHELL=/bin/bash
SourcePackage: linux-signed-hwe-6.5
UpgradeStatus: No upgrade log present (probably fresh install)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-6.5/+bug/2063495/+subscriptions
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