diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c
index cc17c8851..79984e13b 100644
--- a/crypto/dh/dh_key.c
+++ b/crypto/dh/dh_key.c
@@ -217,8 +217,11 @@ static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
 
 	ret=BN_bn2bin(tmp,key);
 err:
-	BN_CTX_end(ctx);
-	BN_CTX_free(ctx);
+	if (ctx != NULL)
+		{
+		BN_CTX_end(ctx);
+		BN_CTX_free(ctx);
+		}
 	return(ret);
 	}
 
diff --git a/crypto/ec/ec2_smpl.c b/crypto/ec/ec2_smpl.c
index a2eb64859..527e6d814 100644
--- a/crypto/ec/ec2_smpl.c
+++ b/crypto/ec/ec2_smpl.c
@@ -281,7 +281,8 @@ int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
 	ret = 1;
 
 err:
-	BN_CTX_end(ctx);
+	if (ctx != NULL)
+		BN_CTX_end(ctx);
 	if (new_ctx != NULL)
 		BN_CTX_free(new_ctx);
 	return ret;
diff --git a/crypto/ec/ec_check.c b/crypto/ec/ec_check.c
index f22c5641a..0e316b4b3 100644
--- a/crypto/ec/ec_check.c
+++ b/crypto/ec/ec_check.c
@@ -113,7 +113,8 @@ int EC_GROUP_check(const EC_GROUP *group, BN_CTX *ctx)
 	ret = 1;
 
 err:
-	BN_CTX_end(ctx);
+	if (ctx != NULL)
+		BN_CTX_end(ctx);
 	if (new_ctx != NULL)
 		BN_CTX_free(new_ctx);
 	if (point)
diff --git a/crypto/ec/ecp_smpl.c b/crypto/ec/ecp_smpl.c
index 75296a367..4d26f8bdf 100644
--- a/crypto/ec/ecp_smpl.c
+++ b/crypto/ec/ecp_smpl.c
@@ -336,7 +336,8 @@ int ec_GFp_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
 	ret = 1;
 
 err:
-	BN_CTX_end(ctx);
+	if (ctx != NULL)
+		BN_CTX_end(ctx);
 	if (new_ctx != NULL)
 		BN_CTX_free(new_ctx);
 	return ret;
diff --git a/crypto/rsa/rsa_gen.c b/crypto/rsa/rsa_gen.c
index 383d6095f..742f8b18e 100644
--- a/crypto/rsa/rsa_gen.c
+++ b/crypto/rsa/rsa_gen.c
@@ -183,8 +183,11 @@ err:
 		RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,ERR_LIB_BN);
 		ok=0;
 		}
-	BN_CTX_end(ctx);
-	BN_CTX_free(ctx);
+	if (ctx != NULL)
+		{
+		BN_CTX_end(ctx);
+		BN_CTX_free(ctx);
+		}
 
 	return ok;
 	}