探伤者报告的缺陷，但我认为这没有意义

Question

这个问题特定于 Flawfinder 报告的模式：

代码段

unsigned char child_report;
...
auto readlen = read(pipefd[0], (void *) &child_report, sizeof(child_report));
if(readlen == -1 || readlen != sizeof(child_report)) {
_ret.failure = execute_result::PREIO ; // set some flags to report to the caller
close(pipefd[0]);
return _ret;
}
...
int sec_read = read(pipefd[0], (void *) &child_report, sizeof(child_report));
child_report = 0; // we are not using the read data at all
// we just want to know if the read is successful or not
if (sec_read != 0 && sec_read != -1) { // if success
_ret.failure = execute_result::EXEC; // it means that the child is not able to exec
close(pipefd[0]);                    // as we set the close-on-exec flag
return _ret;                         // and we do write after exec in the child 
}

我原来Codacy(因此是探伤者(在两个阅读中都报告了此类问题：

Check buffer boundaries if used in a loop including recursive loops (CWE-120, CWE-20).

我不明白。

1. 没有循环。
2. 在第二种情况下，我们根本不使用读取的数据
3. 这不是典型的 C 字符串，我们不依赖于结尾 '\0'

代码中是否有任何我不知道的缺陷？

Answer 1

我最终得出结论，这应该是一个误报。我检查了 Flawfinder 的代码，似乎它基本上是在进行模式匹配。

https://github.com/david-a-wheeler/flawfinder/blob/293ca17d8212905c7788aca1df7837d4716bd456/flawfinder#L1057