do_othername: check for NULL after allocating objtmp

Signed-off-by: NKurt Roeckx <kurt@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>

crypto/x509v3/v3_alt.c

@@ -579,6 +579,8 @@ static int do_othername(GENERAL_NAME *gen, char *value, X509V3_CTX *ctx)
 		return 0;
 	objlen = p - value;
 	objtmp = OPENSSL_malloc(objlen + 1);
+	if (objtmp == NULL)
+		return 0;
 	strncpy(objtmp, value, objlen);
 	objtmp[objlen] = 0;
 	gen->d.otherName->type_id = OBJ_txt2obj(objtmp, 0);