2004-01-08 18:50:13

by john moser

[permalink] [raw]
Subject: Oops 0002

icebox regression # ./memkmemport_test
Testing denied write of /dev/mem... : FAILED
Testing denied mmap write of /dev/kmem... : FAILED
Testing denied open of /dev/port... : FAILED
<1>Unable to handle kernel NULL pointer dereference at virtual address
00000000
printing eip:
c0387645
*pde = 00000000
Oops: 0002 [#3]
CPU: 0
EIP: 0060:[<c0387645>] Tainted: PF
EFLAGS: 00010246
eax: 00000000 ebx: 00000004 ecx: 00000004 edx: 00000000
esi: 080487eb edi: 00000000 ebp: 080487ef esp: d0f55e80
ds: 007b es: 007b ss: 0068
Process memkmemport_tes (pid: 7355, threadinfo=d0f54000 task=dbdd0c80)
Stack: 00000004 00000004 efd516c0 c02b7523 ef5aa9c0 00000004 00000000 c02b6a48
00000000 080487eb 00000004 e69cd140 c02b6dd0 00000004 e69cd160 080487eb
c02b6e39 e69cd140 00000000 00000000 080487eb 00000004 e69cd160 e69cd140
Call Trace: [<c02b7523>] [<c02b6a48>] [<c02b6dd0>] [<c02b6e39>]
[<c02b6dd0>] [<c01ed0e8>] [<c01ed212>] [<c019d417>] [<c019d42f>]
Code: f3 aa 58 59 e9 fc 4c f0 ff b8 f2 ff ff ff e9 b3 9e f0 ff b8
Segmentation fault


regression tools that I pulled out of the grsecurity.net cvs and tested on a PaX patched kernel AND a kernel that I'm working a bit on (without pax), neither should oops. I don't readily reboot to run vanillas. This is a NULL dereference INSIDE the kernel, right? Something's broke, and it does this on 2.6.1-rc2 so whatever it is is probably still broke.

--Bluefox

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2004-01-08 19:34:11

by Randy.Dunlap

[permalink] [raw]
Subject: Re: Oops 0002

On Thu, 8 Jan 2004 10:49:35 -0800 (PST) john moser <[email protected]> wrote:

| icebox regression # ./memkmemport_test
| Testing denied write of /dev/mem... : FAILED
| Testing denied mmap write of /dev/kmem... : FAILED
| Testing denied open of /dev/port... : FAILED
| <1>Unable to handle kernel NULL pointer dereference at virtual address
| 00000000
| printing eip:
| c0387645
| *pde = 00000000
| Oops: 0002 [#3]
| CPU: 0
| EIP: 0060:[<c0387645>] Tainted: PF
| EFLAGS: 00010246
| eax: 00000000 ebx: 00000004 ecx: 00000004 edx: 00000000
| esi: 080487eb edi: 00000000 ebp: 080487ef esp: d0f55e80
| ds: 007b es: 007b ss: 0068
| Process memkmemport_tes (pid: 7355, threadinfo=d0f54000 task=dbdd0c80)
| Stack: 00000004 00000004 efd516c0 c02b7523 ef5aa9c0 00000004 00000000 c02b6a48
| 00000000 080487eb 00000004 e69cd140 c02b6dd0 00000004 e69cd160 080487eb
| c02b6e39 e69cd140 00000000 00000000 080487eb 00000004 e69cd160 e69cd140
| Call Trace: [<c02b7523>] [<c02b6a48>] [<c02b6dd0>] [<c02b6e39>]
| [<c02b6dd0>] [<c01ed0e8>] [<c01ed212>] [<c019d417>] [<c019d42f>]
| Code: f3 aa 58 59 e9 fc 4c f0 ff b8 f2 ff ff ff e9 b3 9e f0 ff b8
| Segmentation fault
|
|
| regression tools that I pulled out of the grsecurity.net cvs and tested on a PaX patched kernel AND a kernel that I'm working a bit on (without pax), neither should oops. I don't readily reboot to run vanillas. This is a NULL dereference INSIDE the kernel, right? Something's broke, and it does this on 2.6.1-rc2 so whatever it is is probably still broke.

Yes, it's a NULL reference inside (some) kernel.

1. Please wrap email lines around 70-72 characters.

2. What kernel version is this? What patches applied?

3. This is the 3rd oops for this kernel. What were the first 2?

4. Please use CONFIG_KALLSYMS=y so that addresses will be
converted to symbols, or run the oops thru ksymoops.


--
~Randy
MOTD: Always include version info.

2004-01-08 21:26:30

by Christian Borntraeger

[permalink] [raw]
Subject: Re: Oops 0002

john moser wrote:
> icebox regression # ./memkmemport_test
> Testing denied write of /dev/mem... : FAILED
[...]
> Oops: 0002 [#3]

You started this testcase as root? I think writing to /dev/kmem as root is
working as designed.
Having an oops after this artificial memory corruption is quite normal.
Your oops is only interesting if this happens with a non-root user.


cheers

Christian