RFR: 8352728: InternalError loading java.security due to Windows parent folder permissions [v2]

[Martin Balao]

On Tue, 15 Apr 2025 18:38:20 GMT, Francisco Ferrari Bihurriet <fferrari at openjdk.org> wrote:

>> Hi, this is a proposal to fix 8352728.
>> 
>> The main idea is to replace [`java.nio.file.Path::toRealPath`](https://docs.oracle.com/en/java/javase/24/docs/api/java.base/java/nio/file/Path.html#toRealPath(java.nio.file.LinkOption...)) by [`java.io.File::getCanonicalPath`](https://docs.oracle.com/en/java/javase/24/docs/api/java.base/java/io/File.html#getCanonicalPath()) for path canonicalization purposes. The rationale behind this decision is the following:
>> 
>> 1. In _Windows_, `File::getCanonicalPath` handles restricted permissions in parent directories. Contrarily, `Path::toRealPath` fails with `AccessDeniedException`.
>> 2. In _Linux_, `File::getCanonicalPath` handles non-regular files (e.g. `/dev/stdin`). Contrarily, `Path::toRealPath` fails with `NoSuchFileException`.
>> 
>> #### Windows Case
>> 
>> @martinuy and I tracked down the `File::getCanonicalPath` vs `Path::toRealPath` behaviour differences in _Windows_. Both methods end up calling the [`FindFirstFileW`](https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-findfirstfilew) API inside a loop for each parent directory in the path, until they include the leaf:
>> 
>> * [`File::getCanonicalPath`](https://github.com/openjdk/jdk/blob/jdk-24-ga/src/java.base/share/classes/java/io/File.java#L618 "src/java.base/share/classes/java/io/File.java:618") goes through the following stack into `FindFirstFileW`:
>>     * [`WinNTFileSystem::canonicalize`](https://github.com/openjdk/jdk/blob/jdk-24-ga/src/java.base/windows/classes/java/io/WinNTFileSystem.java#L473 "src/java.base/windows/classes/java/io/WinNTFileSystem.java:473")
>>     * [`WinNTFileSystem::canonicalize0`](https://github.com/openjdk/jdk/blob/jdk-24-ga/src/java.base/windows/native/libjava/WinNTFileSystem_md.c#L288 "src/java.base/windows/native/libjava/WinNTFileSystem_md.c:288")
>>     * [`wcanonicalize`](https://github.com/openjdk/jdk/blob/jdk-24-ga/src/java.base/windows/native/libjava/canonicalize_md.c#L233 "src/java.base/windows/native/libjava/canonicalize_md.c:233") (here is the loop)
>>     * If `FindFirstFileW` fails with `ERROR_ACCESS_DENIED`, `lastErrorReportable` is consulted, the error is [considered non-reportable](https://github.com/openjdk/jdk/blob/jdk-24-ga/src/java.base/windows/native/libjava/canonicalize_md.c#L139 "src/java.base/windows/native/libjava/canonicalize_md.c:139") and the iteration is stopped [here](https://github.com/openjdk/jdk/blob/jdk-24-ga/src/java.base/windows/native/libjava/canonicalize_md.c#L246-L250 "src/ja...
>
> Francisco Ferrari Bihurriet has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - Do minor adjustments
>    
>    Update copyright year, improve comments and use File::toPath to convert
>    back to Path.
>  - Merge openjdk/master into JDK-8352728
>  - 8352728: InternalError loading java.security due to Windows parent folder permissions

Looks like `File::getCanonicalPath` is more resilient to canonicalization and resolution failures. This observation makes me wonder the following:

1) Can a normalization failure (e.g. return of a partially normalized path) affect relative includes?

2) Can a failure in symlinks resolution (which seems to be ignored) affect relative includes?

Startup will fail if the included file is not found, which is a safe behavior. The problematic scenario would be one in which a different file exists in a location that uses the partially normalized or resolved path as a base, and is not what the "include" properties writer intended. While unlikely, I want to understand if this is possible and a downside of using `File::getCanonicalPath`.

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PR Comment: https://git.openjdk.org/jdk/pull/24465#issuecomment-2811705669