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Re: Calysto v1.5 reports on openldap_v2.4.4alpha

Domagoj Babic wrote:

On 8/20/07, Kurt Zeilenga <kurt@openldap.org> wrote:
On Aug 20, 2007, at 12:02 PM, Domagoj Babic wrote:
Could you please check them out and replace ??? with Yes/No, and
if it's a false positive, write a short explanation.
It seems that most (if not all) of this is simply dereferencing the
NULL result of a failed malloc (or the like) memory allocation.  I
don't consider such derefs of NULL to be bugs in OpenLDAP Software as
it done intentionally.  That is, the expected behavior of OpenLDAP
Software, in general, is to failure abruptly upon malloc(3) failure,
either by dereferencing NULL or abort(3)ing.

I've analyzed quite a few applications out there, and my recommendation would be to insert NULL-checks, and print an appropriate message. If users experience an unexplained crash, they will contribute it to bad code quality, not the current conditions on the machine. The message is clearly useful to the developers.

Probably the highest quality code I've seen so far is ISC BIND, they
check every single pointer before dereference, and every single
data structure for consistency.

So, I guess I can consider ??? marked VCs to be conditions that would crash openldap, right?

calysto v1.5 on openldap_v2.4.4alpha: ??/20
FYI, 2.4.4 is old code.

Are you interested in having the newer one checked?

Feel free to check against CVS HEAD, which will shortly be synced up to become the 2.4.5 release.

But, expanding on Kurt's comments - most of the items you reported are in one-shot client or test code. The probability of an alloc routine returning NULL here is near zero, and since it is in code that is either (a) only used for one-shot tests or (b) only invoked for a single request and then exited, we really don't care. For any cases that you find that are in library code that can be executed multiple times in an app or server, we probably need to pay attention.
-- Howard Chu
Chief Architect, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/