crypto/ec/ecdh_kdf.c:93: error: USE_AFTER_FREE
  call to `EVP_DigestFinal()` eventually accesses memory that was invalidated by call to `free()` on line 81 indirectly during the call to `EVP_DigestInit_ex()`.
Showing all 16 steps of the trace


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

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

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

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

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

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

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

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

crypto/mem.c:245:5: was invalidated by call to `free()`
      243.       }
      244.   #else
      245.       free(str);
                 ^
      246.   #endif
      247.   }

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

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

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

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

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

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

crypto/mem.c:245:5: invalid access occurs here
    243.       }
    244.   #else
    245.       free(str);
               ^
    246.   #endif
    247.   }
