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

Toralf Förster
2014-06-16T17:59:26Z

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 Förster <toralf.foerster@gmx.de> wrote:
>> On 06/16/2014 07:32 PM, Andy Lutomirski wrote:
>>> On Mon, Jun 16, 2014 at 10:29 AM, Richard Weinberger <richard@nod.at> wrote:
>>>> Am 16.06.2014 19:25, schrieb Andy Lutomirski:
>>>>> On Mon, Jun 16, 2014 at 10:21 AM, Richard Weinberger
>>>>> <richard.weinberger@gmail.com> wrote:
>>>>>> On Mon, Jun 16, 2014 at 6:33 PM, Toralf Förster <toralf.foerster@gmx.de> 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