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<p class="MsoNormal"><span style="color:#1F497D">Hello,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Currently we are seeing below 3 patterns of memory leak issue with Openssl 1.1.1i and 1.1.1k version using address santizer option as below:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Direct leak of 208 byte(s) in 2 object(s) allocated from:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #0 0x9ef57b in __interceptor_malloc (/usr/local/bin/autoai/custom_binary+0x9ef57b)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #1 0xffffac627743 in BN_MONT_CTX_new (/usr/lib64/libcrypto.so.1.1+0xaf743)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #2 0xffffac627baf in BN_MONT_CTX_set_locked (/usr/lib64/libcrypto.so.1.1+0xafbaf)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #3 0xffffac6ec77b (/usr/lib64/libcrypto.so.1.1+0x17477b) rsa_ossl_public_decrypt<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #4 0xffffac6f0577 (/usr/lib64/libcrypto.so.1.1+0x178577) RSA_verify_ASN1_OCTET_STRING<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #5 0xffffac6eef1b (/usr/lib64/libcrypto.so.1.1+0x176f1b) pkey_rsa_verify
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #6 0xffffac6b44cf in EVP_DigestVerifyFinal (/usr/lib64/libcrypto.so.1.1+0x13c4cf)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #7 0xffffac8d95c7 (/usr/lib64/libssl.so.1.1+0x515c7) tls_process_key_exchange ->EVP_DigestVerify->EVP_DigestVerifyFinal<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #8 0xffffac8d9b33 (/usr/lib64/libssl.so.1.1+0x51b33) ossl_statem_client_process_message<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #9 0xffffac8d3acb (/usr/lib64/libssl.so.1.1+0x4bacb) state_machine -> read_state_machine -> *process_change->ossl_statem_client_process_message<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #10 0xffffac8c01fb in SSL_do_handshake (/usr/lib64/libssl.so.1.1+0x381fb) via SSL_connect<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #11 0xffffac858f3b (/usr/lib64/libcurl.so.4+0x4ff3b) ossl_connect_step2<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #12 0xffffac85afeb (/usr/lib64/libcurl.so.4+0x51feb) ossl_connect_common<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #13 0xffffac85c1ef (/usr/lib64/libcurl.so.4+0x531ef) Curl_ssl_connect_nonblocking
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #14 0xffffac82c96f (/usr/lib64/libcurl.so.4+0x2396f) https_connecting<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Indirect leak of 2064 byte(s) in 2 object(s) allocated from:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #0 0x9ef57b in __interceptor_malloc (/usr/local/bin/autoai/custom_binary+0x9ef57b)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #1 0xffffac6bf173 in CRYPTO_zalloc (/usr/lib64/libcrypto.so.1.1+0x147173)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #2 0xffffac625fd7 (/usr/lib64/libcrypto.so.1.1+0xadfd7)bn_expand2<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #3 0xffffac6262af in BN_set_bit (/usr/lib64/libcrypto.so.1.1+0xae2af)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #4 0xffffac627a0b in BN_MONT_CTX_set (/usr/lib64/libcrypto.so.1.1+0xafa0b)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #5 0xffffac627bc3 in BN_MONT_CTX_set_locked (/usr/lib64/libcrypto.so.1.1+0xafbc3)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><Curl backtrace is same as above><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Indirect leak of 1536 byte(s) in 5 object(s) allocated from:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #0 0x9ef57b in __interceptor_malloc (/usr/local/bin/autoai/custom_binary+0x9ef57b)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #1 0xffffac6bf173 in CRYPTO_zalloc (/usr/lib64/libcrypto.so.1.1+0x147173)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #2 0xffffac625fd7 (/usr/lib64/libcrypto.so.1.1+0xadfd7) bn_expand2<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #3 0xffffac626143 in BN_copy (/usr/lib64/libcrypto.so.1.1+0xae143)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #4 0xffffac6278a3 in BN_MONT_CTX_set (/usr/lib64/libcrypto.so.1.1+0xaf8a3)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> #5 0xffffac627bc3 in BN_MONT_CTX_set_locked (/usr/lib64/libcrypto.so.1.1+0xafbc3)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><Curl backtrace is same as above><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">After statical analysis we noted that the crypto_malloc and crypto_free functions are further called.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">In these functions we could see debug flags OPENSSL_NO_CRYPTO_MDEBUG and OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE which might provide useful information in debugging this leak issue.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">In this regard we have below queries:-<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">1. Could you please let us know how to enable/check the logs generated by above debug flags ?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">2. We tried one experiment wherein we have disabled flags RSA_FLAG_CACHE_PUBLIC, RSA_FLAG_CACHE_PRIVATE from rsa_ossl_init() function and we can see that above leak does not happen.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> In this regards, are there any known issue/fixes available which we could try.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">2. Any other suggesstion for debugging this memory leak from openssl point of view, would be welcome.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Chetan<o:p></o:p></span></p>
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