crypto/ec/ecdh_kdf.c:92: error: USE_AFTER_FREE
  call to `EVP_DigestFinal()` eventually accesses memory that was invalidated by call to `free()` on line 80 indirectly during the call to `EVP_DigestInit_ex()`.
Showing all 16 steps of the trace


crypto/ec/ecdh_kdf.c:74:12: invalidation part of the trace starts here
72.           || Zlen > ECDH_KDF_MAX)
73.           return 0;
74.       mctx = EVP_MD_CTX_new();
                 ^
75.       if (mctx == NULL)
76.           return 0;

crypto/ec/ecdh_kdf.c:74:12: passed as argument to `EVP_MD_CTX_new`
  72.           || Zlen > ECDH_KDF_MAX)
  73.           return 0;
  74.       mctx = EVP_MD_CTX_new();
                   ^
  75.       if (mctx == NULL)
  76.           return 0;

crypto/ec/ecdh_kdf.c:74:12: return from call to `EVP_MD_CTX_new`
  72.           || Zlen > ECDH_KDF_MAX)
  73.           return 0;
  74.       mctx = EVP_MD_CTX_new();
                   ^
  75.       if (mctx == NULL)
  76.           return 0;

crypto/ec/ecdh_kdf.c:74:5: assigned
  72.           || Zlen > ECDH_KDF_MAX)
  73.           return 0;
  74.       mctx = EVP_MD_CTX_new();
            ^
  75.       if (mctx == NULL)
  76.           return 0;

crypto/ec/ecdh_kdf.c:80:9: when calling `EVP_DigestInit_ex` here
  78.       for (i = 1;; i++) {
  79.           unsigned char mtmp[EVP_MAX_MD_SIZE];
  80.           EVP_DigestInit_ex(mctx, md, NULL);
                ^
  81.           ctr[3] = i & 0xFF;
  82.           ctr[2] = (i >> 8) & 0xFF;

crypto/evp/digest.c:169:1: parameter `ctx` of EVP_DigestInit_ex
    167.   }
    168.   
    169. > int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl)
    170.   {
    171.       EVP_MD_CTX_clear_flags(ctx, EVP_MD_CTX_FLAG_CLEANED);

crypto/evp/digest.c:228:13: when calling `CRYPTO_free` here
    226.       if (ctx->digest != type) {
    227.           if (ctx->digest && ctx->digest->ctx_size)
    228.               OPENSSL_free(ctx->md_data);
                       ^
    229.           ctx->digest = type;
    230.           if (!(ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) && type->ctx_size) {

crypto/mem.c:233:1: parameter `str` of CRYPTO_free
      231.   }
      232.   
      233. > void CRYPTO_free(void *str)
      234.   {
      235.   #ifndef OPENSSL_NO_CRYPTO_MDEBUG

crypto/mem.c:244:5: was invalidated by call to `free()`
      242.       }
      243.   #else
      244.       free(str);
                 ^
      245.   #endif
      246.   }

crypto/ec/ecdh_kdf.c:74:12: use-after-lifetime part of the trace starts here
72.           || Zlen > ECDH_KDF_MAX)
73.           return 0;
74.       mctx = EVP_MD_CTX_new();
                 ^
75.       if (mctx == NULL)
76.           return 0;

crypto/ec/ecdh_kdf.c:74:12: passed as argument to `EVP_MD_CTX_new`
  72.           || Zlen > ECDH_KDF_MAX)
  73.           return 0;
  74.       mctx = EVP_MD_CTX_new();
                   ^
  75.       if (mctx == NULL)
  76.           return 0;

crypto/ec/ecdh_kdf.c:74:12: return from call to `EVP_MD_CTX_new`
  72.           || Zlen > ECDH_KDF_MAX)
  73.           return 0;
  74.       mctx = EVP_MD_CTX_new();
                   ^
  75.       if (mctx == NULL)
  76.           return 0;

crypto/ec/ecdh_kdf.c:74:5: assigned
  72.           || Zlen > ECDH_KDF_MAX)
  73.           return 0;
  74.       mctx = EVP_MD_CTX_new();
            ^
  75.       if (mctx == NULL)
  76.           return 0;

crypto/ec/ecdh_kdf.c:92:18: when calling `EVP_DigestFinal` here
  90.               goto err;
  91.           if (outlen >= mdlen) {
  92.               if (!EVP_DigestFinal(mctx, out, NULL))
                         ^
  93.                   goto err;
  94.               outlen -= mdlen;

crypto/mem.c:233:1: parameter `str` of CRYPTO_free
    231.   }
    232.   
    233. > void CRYPTO_free(void *str)
    234.   {
    235.   #ifndef OPENSSL_NO_CRYPTO_MDEBUG

crypto/mem.c:244:5: invalid access occurs here
    242.       }
    243.   #else
    244.       free(str);
               ^
    245.   #endif
    246.   }
