[EXTERNAL] - Re: Seeing intermittent crash for TLSv1.3

[Michael Wojcik]

> From: openssl-users <openssl-users-bounces at openssl.org> On Behalf Of
> Hubert Kario
> Sent: Tuesday, 23 April, 2024 02:05
> 
> Try using --malloc-fill=af --free-fill=fa ?
> (or some other non-zero values)

Or on a glibc platform (which I'm assuming Rahul's original message referred to, as that looked like a gdb backtrace), enabling libc_malloc_debug with LD_PRELOAD and setting MALLOC_CHECK_ or the equivalent glibc tunable. In my experience it can be a bit of work getting glibc malloc debugging working, and Valgrind is usually a better option; but if, as Rahul reported, valgrind is not diagnosing the issue, glibc malloc debugging is another possible route.

That said, it's not entirely clear to me whether Rahul exhausted the valgrind option, since in the previous message he wrote that "we are not able to see this crash when we are running our debug modules with Purify or Valgrind". I'd suggest running the precise problem scenario — same build, same reproduction sequence — under valgrind (memcheck), and then go through the valgrind output, starting with the post-termination report. If valgrind doesn't identify a problem with the debug build, try it with the release build.

-- 
Michael Wojcik