[Samba] SIGSEGV on CentOS6

[Jeremy Allison]

On Thu, Sep 18, 2014 at 12:12:13PM +0100, Jonathan Knight wrote:
> We're been running the distribution version of Samba 3.6.9 as  DC on Centos
> 6 for a few weeks now with a number of Samba 4 clients.  We have ~20,000
> machine and user accounts in our password database.
> 
> We see a SIGSEGV every 24-48 hours or so in tcopy_passwd.
> 
> I built a Samba 3.6.24 with debugging symbols and waited for a core file
> which we got this morning.
> 
> Looking through the code we can see that there was a machine lookup for one
> of our Samba 4 servers which was handed a duff memory pointer from a
> memcache lookup.  When it tried to dereference the memory pointer the
> SIGSEGV resulted.
> 
> I'm working on the theory that the heap has been corrupted rather than a
> fault with memcache, but I thought I'd just check in here to make sure
> no-one else was seeing the same problems and had already made progress in
> fixing it.

Not a known issue. Can you reproduce under valgrind ?