[stunnel-users] Periodic stunnel 4.34 core dumps on AIX 5.3

[Peter Pentchev]

On Thu, Mar 10, 2011 at 06:02:19PM -0600, Allex, Paul M (USA E D EA STS) wrote:
> Sorry for posting my follow up incorrectly.
> 
> Anyways, I believe I have located the memory leak. In the pthread
> version of create_client (sthreads.c), there is the following code:
> 
> int create_client(int ls, int s, CLI *arg, void *(*cli)(void *)) {
>     pthread_attr_t pth_attr;
> ...
>     pthread_attr_init(&pth_attr);
> ...
>     if(pthread_create(&thread, &pth_attr, cli, arg)) {
> ...
>     return 0;
> }
> 
> The issue here is that pthread_attr_destroy is not being called for
> pth_attr after pthread_create is done. This leaks memory allocated into
> pth_attr by pthread_attr_init.
> 
> http://www.kernel.org/doc/man-pages/online/pages/man3/pthread_attr_init.
> 3.html
> 
> I corrected the code locally and tested, and it appears to no longer
> leak memory for the test I described earlier.
> 
> Patch:
> 
> *** sthreads.orig.c     Thu Mar 10 17:50:03 2011
> --- sthreads.c  Thu Mar 10 17:50:43 2011
> ***************
> *** 313,318 ****
> --- 313,319 ----
>       if(pthread_create(&thread, &pth_attr, cli, arg)) {
>   #ifdef HAVE_PTHREAD_SIGMASK
>           pthread_sigmask(SIG_SETMASK, &oldmask, NULL); /* restore the
> mask */
> +         pthread_attr_destroy(&pth_attr);
>   #endif /* HAVE_PTHREAD_SIGMASK */
>           if(arg)
>               free(arg);
> ***************
> *** 322,327 ****
> --- 323,329 ----
>       }
>   #ifdef HAVE_PTHREAD_SIGMASK
>       pthread_sigmask(SIG_SETMASK, &oldmask, NULL); /* restore the mask
> */
> +     pthread_attr_destroy(&pth_attr);
>   #endif /* HAVE_PTHREAD_SIGMASK */
>       return 0;
>   }
> 
> Thanks,
> 
> Paul Allex

Hmmm, doesn't this point to another little buglet?  Shouldn't
both your new pthread_attr_destroy() and the pthread_attr_create()
that is in the current stunnel code be *outside* the #ifdefs?

Michal, what do you think of the two attached patches?  The first one
moves pthread_attr_create() out of the ifdefs, and the second one is
the modified memory leak patch of Paul's with the destroying happening
outside of the #ifdefs.

G'luck,
Peter

-- 
Peter Pentchev	roam at ringlet.net roam at FreeBSD.org peter at packetscale.com
PGP key:	http://people.FreeBSD.org/~roam/roam.key.asc
Key fingerprint	FDBA FD79 C26F 3C51 C95E  DF9E ED18 B68D 1619 4553
I've heard that this sentence is a rumor.
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