Possible NULL-pointer dereference in lib/util/charset/pull_push.c

[Volker Lendecke]

On Tue, Aug 27, 2013 at 05:15:20PM +0200, Torsten Kurbad wrote:
> Hi all,
> 
> while trying to build a product on top of the samba Python modules, a
> segmentation fault occured, whenever I tried to open a SamDB connection
> to our PDC via ldb's ldap backend.
> 
> Using valgrind, I tracked that down to a NULL-pointer dereference
> occuring in lib/util/charset/pull_push.c, line 41 (Samba 4.0.8 code
> base).
> 
> I somewhat circumvented the segfault by applying the attached patch.
> However, I'm confident that there's a better way to deal with that,
> i.e. preventing the occurence of NULL as the value of src right from
> the start.
> 
> Can someone assist me with this, since I'm quite lost, when it comes to
> C. ;-)

Can you get us a full backtrace of the crash? Get a corefile
of your product, attach to it with gdb and do a "bt full".

Volker

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