kernel panic: bug in sch_sfq.c

[Abraham van der Merwe]

Hi!

I have a box that crashed today. Below is the decoded kernel panic. If you
track down the bug PLEASE send me a patch.

------------< snip <------< snip <------< snip <------------
ksymoops 2.4.8 on i686 2.4.20-rc1.  Options used
     -v vmlinux-2.4.21-pre5 (specified)
     -K (specified)
     -L (specified)
     -O (specified)
     -m System.map-2.4.21-pre5 (specified)

Unable to handle kernel NULL pointer dereference at virtual address 00000004
*pde = 00000000
Oops: 0002
CPU:    0
EIP:    0010:[<c01a5399>]    Not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00010202
eax: 00000000   ebx: c7b9a9e8   ecx: 0000007f   edx: c7a8eef8
esi: c7b9ab08   edi: 000007f0   ebp: c7a8e060   esp: c021deb8
ds: 0018   es: 0018   ss: 0018
Process swapper (pid: 0, stackpage=c021d000)
Stack: c7b9a9e8 c7b9ab08 c7f7ee00 c7b9a860 c7b893c0 c7f7ee00 c7b9a860 00000000
       c01a3507 c7b5c680 7fb9a9f0 c01a339e c7a8e000 ffffffff 00000018 00000006
       c7b9a800 00000018 00000006 c7b9a800 c7b9a9e8 c7b9ab08 c7f7ee00 c01a371c
Call Trace:    [<c01a3507>] [<c01a339e>] [<c01a371c>] [<c019f7a3>] [>c019949d>]
  [<c0115a6a>] [<c01082bd>] [<c0105240>] [<c0105240>] [<c010a528>] [<c0105240>]
  [<c0105240>] [<c0105263>] [<c01052d2>] [<c0105000>] [<c0105027>]
Code: 89 50 04 89 02 8b 5c 24 24 c7 03 00 00 00 00 c7 43 04 00 00

>>EIP; c01a5399 <sfq_dequeue+59/1b0>   <=====

>>esp; c021deb8 <init_task_union+1eb8/2000>

Trace; c01a3507 <htb_dequeue_tree+217/230>
Trace; c01a339e <htb_dequeue_tree+ae/230>
Trace; c01a371c <htb_dequeue+16c/250>
Trace; c019f7a3 <qdisc_restart+13/d0>
Trace; c0115a6a <do_softirq+5a/b0>
Trace; c01082bd <do_IRQ+9d/b0>
Trace; c0105240 <default_idle+0/30>
Trace; c0105240 <default_idle+0/30>
Trace; c010a528 <call_do_IRQ+5/d>
Trace; c0105240 <default_idle+0/30>
Trace; c0105240 <default_idle+0/30>
Trace; c0105263 <default_idle+23/30>
Trace; c01052d2 <cpu_idle+42/60>
Trace; c0105000 <_stext+0/0>
Trace; c0105027 <rest_init+27/30>

Code;  c01a5399 <sfq_dequeue+59/1b0>
00000000 <_EIP>:
Code;  c01a5399 <sfq_dequeue+59/1b0>   <=====
   0:   89 50 04                  mov    %edx,0x4(%eax)   <=====
Code;  c01a539c <sfq_dequeue+5c/1b0>
   3:   89 02                     mov    %eax,(%edx)
Code;  c01a539e <sfq_dequeue+5e/1b0>
   5:   8b 5c 24 24               mov    0x24(%esp,1),%ebx
Code;  c01a53a2 <sfq_dequeue+62/1b0>
   9:   c7 03 00 00 00 00         movl   $0x0,(%ebx)
Code;  c01a53a8 <sfq_dequeue+68/1b0>
   f:   c7 43 04 00 00 00 00      movl   $0x0,0x4(%ebx)

 <0>Kernel panic: Aiee, killing interrupt handler!
------------< snip <------< snip <------< snip <------------

Below are the rules that were installed on the system:

------------< snip <------< snip <------< snip <------------
/sbin/tc qdisc del dev eth0 root
/sbin/tc qdisc del dev eth1 root
/sbin/iptables -t mangle -F qos
/sbin/iptables -t mangle -Z qos
/sbin/tc qdisc add dev eth0 root handle 1: htb default 5 r2q 1
/sbin/tc class add dev eth0 parent 1: classid 1:1 htb rate 96kbit
/sbin/tc class add dev eth0 parent 1:1 classid 1:2 htb rate 96kbit ceil 96kbit
/sbin/tc class add dev eth0 parent 1:2 classid 1:3 htb rate 48kbit ceil 96kbit prio 1
/sbin/tc qdisc add dev eth0 handle 3: parent 1:3 sfq perturb 10 limit 31
/sbin/tc class add dev eth0 parent 1:2 classid 1:4 htb rate 24kbit ceil 96kbit prio 1
/sbin/tc qdisc add dev eth0 handle 4: parent 1:4 sfq perturb 10 limit 31
/sbin/tc class add dev eth0 parent 1:2 classid 1:5 htb rate 16kbit ceil 96kbit prio 2
/sbin/tc qdisc add dev eth0 handle 5: parent 1:5 sfq perturb 10 limit 31
/sbin/iptables -t mangle -A qos -o eth0 -s 66.8.85.0/28 -j CLASSIFY --set-class 1:3
/sbin/iptables -t mangle -A qos -o eth0 -s 66.8.85.80/28 -j CLASSIFY --set-class 1:4
/sbin/iptables -t mangle -A qos -o eth0 -s 192.116.106.192/29 -j CLASSIFY --set-class 1:0
/sbin/iptables -t mangle -A qos -o eth0 -s 66.8.28.48/29 -j CLASSIFY --set-class 1:0
/sbin/tc qdisc add dev eth1 root handle 1: htb default 5 r2q 2
/sbin/tc class add dev eth1 parent 1: classid 1:1 htb rate 512kbit
/sbin/tc class add dev eth1 parent 1:1 classid 1:2 htb rate 256kbit ceil 512kbit
/sbin/tc class add dev eth1 parent 1:2 classid 1:3 htb rate 128kbit ceil 512kbit prio 1
/sbin/tc qdisc add dev eth1 handle 3: parent 1:3 sfq perturb 10 limit 169
/sbin/tc class add dev eth1 parent 1:2 classid 1:4 htb rate 64kbit ceil 512kbit prio 1
/sbin/tc qdisc add dev eth1 handle 4: parent 1:4 sfq perturb 10 limit 169
/sbin/tc class add dev eth1 parent 1:2 classid 1:5 htb rate 32kbit ceil 512kbit prio 2
/sbin/tc qdisc add dev eth1 handle 5: parent 1:5 sfq perturb 10 limit 169
/sbin/iptables -t mangle -A qos -o eth1 -d 66.8.85.0/28 -j CLASSIFY --set-class 1:3
/sbin/iptables -t mangle -A qos -o eth1 -d 66.8.85.80/28 -j CLASSIFY --set-class 1:4
/sbin/iptables -t mangle -A qos -o eth1 -d 192.116.106.192/29 -j CLASSIFY --set-class 1:0
/sbin/iptables -t mangle -A qos -o eth1 -d 66.8.28.48/29 -j CLASSIFY --set-class 1:0
------------< snip <------< snip <------< snip <------------

I've made tons of info available on my home page for you to look at (proc
files, vmlinux, System.map, original panic message, etc.

http://oasis.frogfoot.net/sfq/

-- 

Regards
 Abraham

I saw what you did and I know who you are.

___________________________________________________
 Abraham vd Merwe [ZR1BBQ] - Frogfoot Networks
 P.O. Box 3472, Matieland, Stellenbosch, 7602
 Cell: [phone] Http: http://www.frogfoot.net/
 Email: [e-mail]