RFR: 8328874: Class::forName0 should validate the class name length early

[Alan Bateman]

On Fri, 15 Aug 2025 15:19:35 GMT, Guanqiang Han <ghan at openjdk.org> wrote:

> Validate class name length immediately after GetStringUTFLength() in Class.forName0. This prevents potential issues caused by overly long class names before they reach later code that would reject them, throwing ClassNotFoundException early.

src/java.base/share/native/libjava/Class.c line 119:

> 117:         JNU_ThrowClassNotFoundException(env, msg);
> 118:         return 0;
> 119:     }

I wonder if it's time to hoist these checks so that the checking is in a more discoverable place.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26802#discussion_r2279296271