[Pkg-samba-maint] Bug#404266: smbclient: nmbclient segfaults when asked to lookup a name through avahi

[Michael Schurter]

Steve Langasek wrote:
> On Fri, Dec 22, 2006 at 07:05:17PM -0500, Norman Ramsey wrote:
>> Package: smbclient
>> Version: 3.0.23d-2+b1
>> Severity: important
> 
>> The following command causes a segfault:
> 
>>   smbclient -L bloodhound.local -N
> 
>> The machine 'bloodhound.local' is a Windows XP machine running Apple's
>> 'Bonjour for Windows'.  As you can see below, other apps can find it:
> 
>>   : nr at curlycoat 10308 ; avahi-resolve -4 -n bloodhound.local
>>   bloodhound.local        192.168.2.33
> 
>> I've attached an strace output from the segfaulting run and also my smb.conf.
> 
> Please provide a backtrace using gdb instead of this strace.
> 
> It happens that I'm able to reproduce such a failure here:
> 
> (gdb) bt
> #0  0x080d364d in timeval_add ()
> #1  0xb7fd181b in mdns_query_name () from /usr/lib/libnss_mdns4_minimal.so.2
> #2  0xb7fd00d0 in _nss_mdns4_minimal_gethostbyname2_r () from /usr/lib/libnss_mdns4_minimal.so.2
> #3  0xb7fd02a6 in _nss_mdns4_minimal_gethostbyname_r () from /usr/lib/libnss_mdns4_minimal.so.2
> #4  0xb7d9d48b in gethostbyname_r@@GLIBC_2.1.2 () from /lib/tls/libc.so.6
> #5  0xb7d9cdde in gethostbyname () from /lib/tls/libc.so.6
> #6  0x080c96d3 in internal_resolve_name ()
> #7  0x080ca218 in resolve_name ()
> #8  0x08098a59 in cli_connect ()
> #9  0x080ad596 in cli_cm_shutdown ()
> #10 0x080adb7f in cli_cm_open ()
> #11 0x080686e0 in main ()
> (gdb)
> 
> that looks like a bug in nss_mdns, not in smbclient...
> 

You are correct.  I posted about this here:
http://michael.susens-schurter.com/blog/2006/11/29/mdns-crashes-samba/

Moral of the story: its been submitted as an upstream bug to Avahi.

Hope that helps.

Michael Schurter