I believe https://github.com/openssl/openssl/commit/a7a44ba55cb4f884c6bc9ceac90072dea38e66d0 https://github.com/openssl/openssl/commit/a7a44ba55cb4f884c6... is

I believe https://github.com/openssl/openssl/commit/a7a44ba55cb4f884c6bc9ceac90072dea38e66d0 https://github.com/openssl/openssl/commit/a7a44ba55cb4f884c6... is it. The fix is intermixed with some code cleanups, but it seems to be in mul_add_c2 where a carry got dropped.