SerenityOS/serenity

Everywhere: Audit usages of LexicalPath

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#21,450 创建于 2023年10月14日

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 (1 评论) (0 反应) (0 负责人)C++ (33,171 star) (3,328 fork)batch import
help wanted

描述

Given directory tree

./
  a/
    b/
  e -> a/b

e/.. will refer to a, not .. However, since Directory::create lexically canonicalizes path, running Directory::create("e/..", Directory::CreateDirectories::No) will result in . being opened.

This results in inconsistency between our tar and GNU's tar if ran from . with arguments -cv e/.. -f /dev/null. I'm sure this is not the only place where we assume LexicalPath::canonicalize does not change what path refers to.

Although such resolution is not the most intuitive behavior, I think it should be fixed for the sake of consistency.

I am planning on addressing situation with paths altogether, so I made this issue mostly as a reminder for myself.

贡献者指南

技术栈
cpp
领域
backend
议题类型
bug
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
4
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
half day
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
stale
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
C++file system concepts
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
20
研究方向
The issue concerns inconsistent behavior of LexicalPath::canonicalize in SerenityOS, particularly when used with symlinks and parent directory references. The bug manifests in Directory::create where a path like 'e/..' is canonicalized to '.', leading to incorrect results compared to GNU tar. The fix likely requires auditing all usages of LexicalPath to ensure canonicalization does not change the target of paths with symlinks. The author has stated intent to address this, but no assignee or PR exists yet. Look at the LexicalPath implementation and all callers of canonicalize, especially in tar related code.