memory still reachable post calling SSL_CTX_free

[Tiwari, Hari Sahaya]

Hi,
I need one clarification on routine SSL_CTX_free(). I see the memory is not freed even after calling this SSL_CTX_free().

I have a simple test program, which just does SSL_CTX_new() and  SSL_CTX_free().

#include<stdio.h>
#include <openssl/ssl.h>

int main()
{
    const SSL_METHOD *method;
    SSL_CTX *ctx = NULL;
    OPENSSL_init_ssl(0, NULL);
    method = TLS_method();
    ctx = SSL_CTX_new(method);
    if ( ctx == NULL ) {
        return(-1);
    }
    SSL_CTX_free(ctx);
    ctx=NULL;
    sleep(300);
}

If the program is terminated after it enters the sleep, I am seeing memory is still reachable in valgrind.

Here is output from valgrind,

==443000== 10,224 bytes in 426 blocks are still reachable in loss record 593 of 594
==443000==    at 0x4C34F0B: malloc (vg_replace_malloc.c:307)
==443000==    by 0x525D775: OPENSSL_LH_insert (in /usr/lib64/libcrypto.so.1.1.1g)
==443000==    by 0x522DDB2: ??? (in /usr/lib64/libcrypto.so.1.1.1g)
==443000==    by 0x522E1CF: ERR_load_strings_const (in /usr/lib64/libcrypto.so.1.1.1g)
==443000==    by 0x4E79083: ERR_load_SSL_strings (in /usr/lib64/libssl.so.1.1.1g)
==443000==    by 0x4E790BC: ??? (in /usr/lib64/libssl.so.1.1.1g)
==443000==    by 0x5DABCD6: __pthread_once_slow (in /usr/lib64/libpthread-2.28.so)
==443000==    by 0x52C4ADC: CRYPTO_THREAD_run_once (in /usr/lib64/libcrypto.so.1.1.1g)
==443000==    by 0x4E794FA: OPENSSL_init_ssl (in /usr/lib64/libssl.so.1.1.1g)
==443000==    by 0x4E7D371: SSL_CTX_new (in /usr/lib64/libssl.so.1.1.1g)
==443000==    by 0x400749: main (in /home/hari/a.out)

SSL_CTX_free is already called before sleep(), but memory is still hanging around.
Is there something I am missing here? Do I need to follow some other steps ?
This memory leak is impacting our long term running processes, which allocate and free context.
Any pointers will be very helpful.

Thanks,
Hari.
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