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Re: Exception when runing libcurl v7.49.0 with mbedTLS

From: Ray Satiro via curl-library <>
Date: Sun, 5 Jun 2016 22:53:24 -0400

On 6/5/2016 9:11 AM, Moti Avrahami wrote:
> Recently I upgraded libcurl to v7.49.0 and now I’m getting exception
> when connecting to some FTPS servers.
> The exception is about “Access violation reading location” and the
> callstack begin from mbedTLS.c in this function:
> void Curl_mbedtls_session_free(void *ptr)
> {
> mbedtls_ssl_session_free(ptr);
> free(ptr);
> }
> The second command (free) go deep to this:
> File: C:\Program Files (x86)\Microsoft Visual Studio
> 9.0\VC\crt\src\dbgheap.c
> Line: 1132
> Expression: _CrtIsValidHeapPointer(pUserData)
> Does someone else encounter it?

I haven't, but I don't have a mbedTLS setup for Visual Studio at the
moment. FTPS with session resume is working here with mbedTLS since the
session resume fix [1]. The code you cite is correct because
mbedtls_ssl_session_free only frees what's in the session object but not
the object itself. That is why it's followed by a call to free.

What do you mean by some ftps servers? Is there a specific server? Can
you try to reproduce in the latest curl master and check if it's a
specific server type that's giving you the problem?


List admin:
Received on 2016-06-06