Re: [libmicrohttpd] Memory leak when using MHD in TLS mode with bad certificates

[Christian Grothoff]

Dear Nicolas,

Thanks for reporting, the attached patch fixes it. Also in Git as
dad0746a..302d3811.

Happy hacking!

Christian

On 1/11/19 4:11 PM, Nicolas Mora wrote:
> Hello,
> 
> While testing memory leaks in my code with valgrind, I found the
> following problem, but I'm not sure if it comes from MHD or GnuTLS, or
> even my use of libmicrohttpd.
> 
> I use libmicrohttpd 0.9.62 and GnuTLS 3.6.5 on Debian.
> 
> When you execute MHD_start_daemon with TLS support but use bad
> certificates, the function MHD_start_daemon returns NULL, which is
> expected, but seems to leak data.
> Although, with the same code but with a valid certificate, there is no
> memory leak.
> 
> Valgrind reports the following problem:
> ==7543== 6,336 (168 direct, 6,168 indirect) bytes in 1 blocks are
> definitely lost in loss record 3 of 3
> ==7543==    at 0x4837B65: calloc (vg_replace_malloc.c:752)
> ==7543==    by 0x4A92966: gnutls_certificate_allocate_credentials (in
> /usr/lib/x86_64-linux-gnu/libgnutls.so.30.23.0)
> ==7543==    by 0x4864BCB: MHD_TLS_init (daemon.c:602)
> ==7543==    by 0x4864BCB: MHD_start_daemon_va (daemon.c:6165)
> ==7543==    by 0x486538A: MHD_start_daemon (daemon.c:4674)
> ==7543==    by 0x10932B: main (minimal_example.c:133)
> 
> I have attached a modified minimal_example.c to show the problem.
> 
> /Nicolas

leak.diff
Description: Text Data

signature.asc
Description: OpenPGP digital signature