Red Hat Bugzilla – Bug 219488
kernel panic removing devices from a teql queuing discipline
Last modified: 2008-01-08 03:48:23 EST
Description of problem:
Removing devices from a teql queuing discipline being used to equalise traffic
over a group of interfaces can cause the kernel to panic if there is traffic
going through the interface at the time.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Setup a teql0 interface with one or more underlying interfaces:
tc qdisc add dev eth0 root teql0
tc qdisc add dev eth1 root teql1
ifconfig teql0 inet ...
2. Send traffic through the teql0 interface (I use a flood ping):
ping -s 1200 -f ...
3. Drop the underlying interface(s) from the equaliser:
tc qdisc del dev eth0 root && tc qdisc del dev eth1 root
Kernel panics - the panic is attached.
Kernel doesn't panic.
Created attachment 143525 [details]
The panic is in __teql_resolve (which has been inlined into teql_master_xmit) in
net/sched/sch_teql.c at this line:
if (n && n->tbl == mn->tbl &&
Specifically the dereference of n->tbl is faulting as n is not valid.
Any news on this?
Still happening in F7 with kernel 22.214.171.124-91.fc7...
Reported to netdev.
(This is a mass-update to all current FC6 kernel bugs in NEW state)
I'm reviewing this bug list as part of the kernel bug triage project, an attempt
to isolate current bugs in the Fedora kernel.
I am CC'ing myself to this bug, however this version of Fedora is no longer
Please attempt to reproduce this bug with a current version of Fedora (presently
Fedora 8). If the bug no longer exists, please close the bug or I'll do so in a
few days if there is no further information lodged.
Thanks for using Fedora!
This was fixed by the netdev guys and the fix made it into 126.96.36.199 and we have
been running 188.8.131.52-34.fc7 on the system in question since 13th December
without any problems.
In fact our ISP had some problems last night which meant this got throughly
exercised as my monitoring code took interfaces in and out of the bond on
several occasions without any panic.