Re: 3.15: kernel BUG at kernel/auditsc.c:1525!

[Toralf FÃrster]

On 06/16/2014 07:50 PM, Andy Lutomirski wrote:
> cc: eparis.  This might be a new audit bug.
> 
> On Mon, Jun 16, 2014 at 10:36 AM, Toralf FÃrster <toralf.foerster@xxxxxx> wrote:
>> On 06/16/2014 07:32 PM, Andy Lutomirski wrote:
>>> On Mon, Jun 16, 2014 at 10:29 AM, Richard Weinberger <richard@xxxxxx> wrote:
>>>> Am 16.06.2014 19:25, schrieb Andy Lutomirski:
>>>>> On Mon, Jun 16, 2014 at 10:21 AM, Richard Weinberger
>>>>> <richard.weinberger@xxxxxxxxx> wrote:
>>>>>> On Mon, Jun 16, 2014 at 6:33 PM, Toralf FÃrster <toralf.foerster@xxxxxx> wrote:
>>>>>>> $ cat syscall.c
>>>>>>> #include <unistd.h>
>>>>>>> #include <sys/syscall.h>
>>>>>>> int main(){return syscall(1000)!=-1;}
>>>>>
>>>>> What architecture are you building for?  On i386 and x86_64, 1000
>>>>> shouldn't be big enough to trigger this.
>>>>
>>>> Toralf, is this an UML kernel?
>>>>
>>>
>>> I'm also interested in the userspace architecture.  If it's x32
>>> userspace, then I'm not surprised that there's a problem.
>>
>> It is a x86 system (ThinkPad T420) - not x32.
> 
> I don't think this is CVE-2014-3917.  It looks like you're hitting this BUG:
> 
> BUG_ON(context->in_syscall || context->name_count);
> 
> Can you send the output of:
> 
> auditctl -l [run as root]
> 
> and
> 
> dmesg |grep audit
> 
> Are you using ptrace or anything like that (e.g. strace) when you
> trigger this?  Are you using a funny glibc version?  Do you have
> selinux or something like that enabled?
> 
> --Andy
> 
n22 ~ # auditctl -l
LIST_RULES: exit,never arch=1073741827 (0x40000003) syscall=read,write,open,close,brk,fcntl,dup2,mmap,munmap,stat,fstat,nanosleep,rt_sigaction


no ptrace/strace/SELinux, this is a stable x86 Gentoo Linux, glibc is 2.17, unstable are just KDE + Co.

(@Richard: no. it is not an UML guest, I just stumbled over this while I tried to upgrade an unstable ~x86 Gentoo UML image using chroot)

The trigger is just given by that C one-liner and kernel 3.15 (erm, I did not checked, if 3.14.x hit its too)

-- 

Toralf

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