Bug#565951: libc6 weird memory corruption error while using custom module in apache2-mpm-prefork

[Aurelien Jarno <aurelien@aurel32.net>]

On Wed, Jan 20, 2010 at 12:25:12AM +0100, Radek Antoniuk wrote:
> Package: libc6
> Version: 2.7-18
> Severity: normal
> 
> I am getting a segfault or segabort &  stacktrace in apache error logs while invoking custom module by apache2-mpm-prefork with php5.
>     *** glibc detected *** /usr/sbin/apache2: malloc(): memory corruption: 0x0847b468 *** 
>     ======= Backtrace: ========= 
>     /lib/libc.so.6[0xb7d9a845] 
>     /lib/libc.so.6[0xb7d9cde2] 
>     /lib/libc.so.6(__libc_malloc+0x96)[0xb7d9e586] 
>     /lib/libc.so.6[0xb7d8b4ff] 
>     /lib/libc.so.6(fopen+0x2c)[0xb7d8b5cc] 
>     /lib/libnss_files.so.2[0xb6d9aa80] 
>     /lib/libnss_files.so.2(_nss_files_getprotobyname_r+0x37)[0xb6d9b067] 
>     /lib/libc.so.6(getprotobyname_r+0xa2)[0xb7e12302] 
>     /lib/libc.so.6(getprotobyname+0x77)[0xb7e12197] 
>     /usr/lib/php5/20060613+lfs/mrl.dll(mlSndRcv+0x1e3)[0xb60f6d93] 
>     /usr/lib/php5/20060613+lfs/mrl.dll(__call_mrldll+0x556)[0xb60e4558] 
> 
> It looks like it is triggered by getprotobyname or libnss...
> Also, it is not easily reproducible, i.e. it happens occasionally, 4-5 times a day on a busy server.
> Any ideas?
> 

It is most probably triggered by a higher level function. Where does
/usr/lib/php5/20060613+lfs/mrl.dll comes from?

-- 
Aurelien Jarno	                        GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net