[Samba] stack smashing problem

[simo]

On Sun, 2006-05-14 at 18:01 -0700, Jeremy Allison wrote:
> On Mon, May 15, 2006 at 12:07:10AM +0200, Matthias et Laura wrote:
> > Hi all,
> > 
> > I have a problem with my smbd daemon, on a hardened linux from scratch 
> > server :
> > kernel 2.6.24.6
> > glibc 2.3.6 with fstack protector
> > grsecurity 2.1.8 patch
> > gcc 3.4.5 with stack smashing protector
> > samba 3.0.22
> > 
> > When starting smbd, I do not have any problem, the daemon is running, 
> > but all his childs die.
> > I have the following log message, repeated several times :
> > smbd: stack smashing attack in function open_sockets_smbd()
> > 
> > So it seems that the open_sockets_smbd function does something that the 
> > stack smashing protection find weird.
> > Do you have any idea ?
> 
> More details please. What is the "stack smashing protector" and
> what does it do ?

One of the many "security" techniques to prevent stack overflow attacks
IIRC.

A couple of pointers from a quick search on the mighty Google from
better explanations
http://www.trl.ibm.com/projects/security/ssp/
http://en.wikipedia.org/wiki/Stack-smashing_protection


-- 
Simo Sorce
Samba Team GPL Compliance Officer
email: idra at samba.org
http://samba.org