[Samba] [3.2.0] Off by one error

[Jeremy Allison]

On Wed, Jul 02, 2008 at 02:09:48PM -0400, James Kosin wrote:
> -----Original Message-----
> From: Jeremy Allison [mailto:jra at samba.org] 
> Sent: Wednesday, July 02, 2008 12:57 PM
> To: James Kosin
> Cc: samba at lists.samba.org
> Subject: Re: [Samba] [3.2.0] Off by one error
> 
> On Wed, Jul 02, 2008 at 12:32:46PM -0400, James Kosin wrote:
> > Jerry,
> > 
> > The 3.2.0 release is reporting this in the log.nmbd
> > [root at beta samba]# cat log.nmbd
> > [2008/07/02 12:26:52,  0] nmbd/nmbd.c:main(849)
> >   nmbd version 3.2.0 started.
> >   Copyright Andrew Tridgell and the Samba Team 1992-2008
> > [2008/07/02 12:26:52,  0] lib/util_str.c:safe_strcpy_fn(709)
> >  ERROR: string overflow by 1 (16 - 15) in safe_strcpy [192.168.100.20/24]
> >  
> >  Other than this issue; no real problems.
> 
> Great (the no problems part) ! Can you attach with gdb to this error
> message and get a backtrace when it occurs please ?
> 
> Thanks,
> 
> 	Jeremy.
> 
> ---
> Jeremy,
> 
> I'd need some pointers, I'm not all that familiar with gdb, and there is no way to stop on the error.  NMDB still runs after displaying this; so, I don't think a back-trace will help find it when I kill the process.

What you can do is attach to the running process with :

gdb /usr/local/samba/sbin/nmbd
b lib/util_str.c:safe_strcpy_fn:709
attach <pid>
continue

Then when the breakpoint triggers you can type :

bt

to get the backtrace, and also go up the stack
and type out the local variables.

If it happens every time you start nmbd then
that's easier, just type :

gdb --args /usr/local/samba/sbin/nmbd -i
b lib/util_str.c:safe_strcpy_fn:709
run

Thanks !

Jeremy