Potential memory corruption in shutdown due to multiple call curl_easy_cleanup()

[adamhan-hitachi]

Query/Question
In Curl transport layer, is it possible to have multiple instances of CurlConnection?

The reason to ask is that I captured back trace for memory corruption during application shutdown as attached. The stack shows that was corrupted in curl_easy_cleanup(), which is called by CurlConnection's destructor. Hence, it could explain that if there are multiple CurlConnection instances in CurlConnectionPool.

Otherwise, I need to explore other reason.

Why is this not a Bug or a feature Request?
It may be a bug. But I haven't reproduce it in unit test. It would be easies to check from design perspective.

Setup (please complete the following information if applicable):

• OS: Debian 11
• IDE : Self build by Bazel / CMake
• Version of the Library used: https://github.com/Azure/azure-sdk-for-cpp/releases/tag/azure-security-attestation_1.1.0
• libcurl/7.88.1 OpenSSL/1.1.1n

Information Checklist
Kindly make sure that you have added all the following information above and checkoff the required fields otherwise we will treat the issuer as an incomplete report

• [ x] Query Added
• [ x] Setup information Added

[kysucix]

Could you try is this pr is fixing your memory leak? ClickHouse#7

[adamhan-hitachi]

Could you try is this pr is fixing your memory leak? ClickHouse#7

Thanks for the suggestion. I checked my version, it seems already changed to use unique pointer to manage Curl handle, as shown in the code snippet below -
m_handle = Azure::Core::_internal::UniqueHandle(curl_easy_init());

In my version, to release unique pointer above will call curl_easy_cleanup() as shown in following snippet -
template <> struct UniqueHandleHelper
{
using type = BasicUniqueHandle<CURL, curl_easy_cleanup>;
}

Is there equivalent to yours?

[kysucix]

I think in the pr I mentioned it's different. The unique_ptr is created passing curl_easy_cleanup() as a Deleter.

[kysucix]

It looks like the memory leak addressed in the link above is already solved in #3995