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https://issues.apache.org/jira/browse/THRIFT-5932?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jens Geyer updated THRIFT-5932:
-------------------------------
    Component/s: Compiler (General)

> saferealpath() on Windows can strcpy() an arbitrarily long path into caller 
> storage
> -----------------------------------------------------------------------------------
>
>                 Key: THRIFT-5932
>                 URL: https://issues.apache.org/jira/browse/THRIFT-5932
>             Project: Thrift
>          Issue Type: Bug
>          Components: Compiler (General)
>            Reporter: Pengpeng Hou
>            Priority: Major
>
> Hi,
> I rechecked current upstream head and this Windows fallback still looks 
> unsafe.
> In `compiler/cpp/src/thrift/main.cc`, `saferealpath()` uses 
> `GetFullPathNameA()` on Windows and then falls back to copying the original 
> path into `resolved_path` with:
>     if (len == 0 || len > MAX_PATH - 1)
> {       strcpy(resolved_path, path);     }
> else
> {       strcpy(resolved_path, buf);     }
> The fallback does not know the actual size of `resolved_path`, and the 
> callers typically pass a fixed stack buffer such as `THRIFT_PATH_MAX` in the 
> compiler front end. If the input `.thrift` path is too long, or if 
> `GetFullPathNameA()` fails, this code copies the raw path into the caller 
> buffer without any local bound check.
> I rechecked the current code and did not find any capacity-aware copy or 
> rejection of overlong paths before the `strcpy()`.
>  
> *How to reproduce*
> 1. Run the Thrift C++ compiler on Windows.
> 2. Pass a very long `.thrift` file path so that `GetFullPathNameA()` returns 
> 0 or a length greater than `MAX_PATH - 1`.
> 3. The fallback path calls `strcpy(resolved_path, path)`.
> 4. If the caller's `resolved_path` buffer is the usual fixed stack buffer, 
> the copy can overflow it.
>  



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