Subject: Re: BUG: unable to handle kernel NULL pointer dereference at virtual address 000000b0

From: Eric Dumazet <[email-masked]>
Date: Wed, 17 Oct 2007 12:38:06 +0200

Krzysztof Oledzki a écrit :
> 
> 
> On Wed, 17 Oct 2007, Eric Dumazet wrote:
> 
>> Krzysztof Oledzki a écrit :
>>> Hello,
>>>
>>> Today I found in my logs:
>>>
>>> BUG: unable to handle kernel NULL pointer dereference at virtual 
>>> address 000000b0
>>>  printing eip:
>>> 78395f65
>>> *pde = 00000000
>>> Oops: 0000 [#1]
>>> PREEMPT SMP
>>> CPU:    0
>>> EIP:    0060:[<78395f65>]    Not tainted VLI
>>> EFLAGS: 00210286   (2.6.22.9 #1)
>>> EIP is at __ip_route_output_key+0x412/0x722
>>> eax: 80000000   ebx: 00000000   ecx: 5dd2b1c3   edx: 00000000
>>> esi: 00000000   edi: d44c7e30   ebp: ec8c4980   esp: d44c7ddc
>>> ds: 007b   es: 007b   fs: 00d8  gs: 0033  ss: 0068
>>> Process smtpd (pid: 12479, ti=d44c6000 task=9e759510 task.ti=d44c6000)
>>> Stack: d44c7e7c d44c7e7c d44c7eb8 00000000 d44c7e7c 00000000 00000000 
>>> 00000005
>>>        00000000 ffffffff 5dd2b1c3 00000000 00000000 00000000 00000000 
>>> 00000000
>>>        00000000 00000000 00000000 00000000 00000000 00030000 00000000 
>>> d44c7e7c
>>> Call Trace:
>>>  [<78396280>] ip_route_output_flow+0xb/0x3e
>>>  [<783b2b29>] ip4_datagram_connect+0x1c9/0x308
>>>  [<783ba70a>] inet_dgram_connect+0x45/0x4e
>>>  [<7837135e>] sys_connect+0x72/0x9c
>>>  [<78371607>] sock_map_fd+0x41/0x4a
>>>  [<7840d1b1>] _spin_lock+0x33/0x3e
>>>  [<7840d623>] _spin_unlock+0x25/0x3b
>>>  [<78371607>] sock_map_fd+0x41/0x4a
>>>  [<78372792>] sys_socketcall+0x8f/0x242
>>>  [<7813e99c>] trace_hardirqs_on+0x122/0x14c
>>>  [<78103dc6>] sysenter_past_esp+0x8f/0x99
>>>  [<78103d96>] sysenter_past_esp+0x5f/0x99
>>>  =======================
>>> Code: fa e0 00 00 00 75 07 c6 44 24 56 05 eb 14 81 fa f0 00 00 00 0f 
>>> 84 e1 02 00 00 84 c0 0f 84 d9 02 00 00 8b 44 24 0c 0d 00 00 00 80 
>>> <f6> 86 b0 00 00 00 08 0f 44 44 24 0c 89 44 24 0c b8 01 00 00 00
>>> EIP: [<78395f65>] __ip_route_output_key+0x412/0x722 SS:ESP 0068:d44c7ddc
>>>
>>> Shortly before it there was:
>>> Oct 17 07:17:55 cougar postfix/master[3400]: warning: process 
>>> /usr/lib/postfix/smtpd pid 12479 killed by signal 11
>>>
>>> Best regards,
>>>
>>>
>>>                 Krzysztof Olędzki
>>
>> Hello Krzysztof
>>
>> Could you give us some details about this ? kernel version at least.
> 
> Yes, I was little to hurry sending this bug report. Anyway, it is 
> 2.6.22.9 like mentioned in the oops: EFLAGS: 00210286 (2.6.22.9 #1)
> 
>> (you could for example take a look at REPORTING-BUGS, or run
>> scripts/ver_linux)
> 
> Linux cougar 2.6.22.9 #1 SMP PREEMPT Wed Oct 3 10:24:19 CEST 2007 i686 
> Intel(R) Pentium(R) D CPU 3.20GHz GenuineIntel GNU/Linux
> 
> Gnu C                  4.1.2
> Gnu make               3.81
> binutils               2.17
> util-linux             2.12r
> mount                  2.12r
> module-init-tools      3.2.2
> e2fsprogs              1.40.2
> Linux C Library        > libc.2.5
> Dynamic linker (ldd)   2.5
> Procps                 3.2.7
> Net-tools              1.60
> Kbd                    1.12
> Sh-utils               6.9
> 

Yes indeed, version was on your initial report.

It seems this kernel is unusual (VMSPLIT_2G_OPT instead of stdandard 
VMSPLIT_3G), any chance you provide full .config ?