[Kernel-packages] [Bug 2063495] [NEW] Kernel soft lockup occures in `fib6_select_path` function

2024-04-25 Thread Omid
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

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux-signed-hwe-6.5 in Ubuntu.
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


-- 
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp


[Kernel-packages] [Bug 2063495] Re: Kernel soft lockup occures in `fib6_select_path` function

2024-04-25 Thread Omid
** Description changed:

  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.
+ arises when the linked list is unexpectedly deleted (its head eference
+ count equals zero), leading to an infinite loop. This results in a soft
+ lockup that 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
+  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)

** Description changed:

  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 head eference
- count equals zero), leading to an infinite loop. This results in a soft
- lockup that triggers a system panic due to the watchdog timer.
+ arises when the linked list is unexpectedly deleted (its list-head
+ reference count equals zero), leading to an infinite loop. This results
+ in a soft lockup that 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)

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux-signed-hwe-6.5 in Ubuntu.
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 list-head reference count equals zero),
  leading to an infinite loop. This results in a soft lockup that
  triggers a system panic due to the watchdog timer.

  It's worth noting that this is a longstanding issue