[Pkg-samba-maint] Bug#526325: samba: Segfaults in rep_strlcpy

[Steve Langasek]

On Thu, Apr 30, 2009 at 01:56:05PM +0100, Sam Morris wrote:
> Package: samba
> Version: 2:3.3.3-1
> Severity: normal

> Over the last couple weeks I have received about twenty mails telling me that
> Samba segfaulted. They all have the following backtrace:

> #0  0x00007fa78606b4a5 in __libc_waitpid (pid=459, stat_loc=0x7fff914c8b1c,
>     options=0) at ../sysdeps/unix/sysv/linux/waitpid.c:32
> #1  0x00007fa78600a1e1 in do_system (
>     line=0x20ffa10 "/usr/share/samba/panic-action 30781")
>     at ../sysdeps/posix/system.c:149
> #2  0x0000000000599b00 in smb_panic (why=<value optimized out>)
>     at lib/util.c:1679
> #3  0x0000000000587277 in sig_fault (sig=11) at lib/fault.c:46
> #4  <signal handler called>
> #5  0x0000000000575d69 in rep_strlcpy (d=0x7fff914c901c "", s=0x0, bufsize=256)
>     at lib/replace/replace.c:64
> #6  0x00000000005a6e3e in connections_fetch_entry (mem_ctx=0x0,
>     conn=<value optimized out>, name=0x0) at lib/conn_tdb.c:65
> #7  0x0000000000487439 in yield_connection (conn=0x2114970, name=0x0)
>     at smbd/connection.c:33
> #8  0x00000000004aba9c in close_cnum (conn=0x2114970, vuid=0)
>     at smbd/service.c:1328

Very unusual.  This is happening from the line:

        yield_connection(conn, lp_servicename(SNUM(conn)));

which means that a) it's happening on shutdown of a connection, so the fact
that it's not showing up as a service disruption is somewhat expected; and
b) the internal "service number" for the connection being closed doesn't
have an associated name.

Could you set debug level = 3 in your smb.conf, restart, find the
corresponding backtrace in the samba log, and send us as complete as
possible a copy of that log, covering the period from the connection to the
crash?

Please also forward a copy of your smb.conf.

-- 
Steve Langasek                   Give me a lever long enough and a Free OS
Debian Developer                   to set it on, and I can move the world.
Ubuntu Developer                                    http://www.debian.org/
slangasek at ubuntu.com                                     vorlon at debian.org