On Mon, 20 Apr 2026 19:58:14 GMT, Joel Sikström <[email protected]> wrote:
> Hello, > > When looking at the usages of > `InstanceKlass::get_inline_type_field_klass_or_null` I saw that > `SystemDictionary::try_preload_from_loadable_descriptors` uses the returned > value even though it may be null, which can result in a SIGSGV. This change > aligns well with what is done just above in > `SystemDictionary::preload_from_null_free_field`, using the local variable > `name` instead of getting the name from the klass. > > Given the right conditions this will result in a crash, but it seems rare as > it requires "the stars to be aligned just right" for it to happen. > > I'm not sure how much testing testing there is for classes which have inlined > and non-inlined fields in them in connection to the code being changed. Such > classes would result in an inline_layout_info_array having null-entires, > since it is a sparse array. > > Testing: > * Oracle's tier1-3 > * Testing with a local reproducer that this does not crash with the changes > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). This pull request has now been integrated. Changeset: e391f76e Author: Joel Sikström <[email protected]> URL: https://git.openjdk.org/valhalla/commit/e391f76e7db834f50c1a0af466daf95a65a79f23 Stats: 8 lines in 1 file changed: 0 ins; 2 del; 6 mod 8382560: [lworld] Unsafe access to klass name in SystemDictionary::try_preload_from_loadable_descriptors Reviewed-by: matsaave, aboldtch, fparain ------------- PR: https://git.openjdk.org/valhalla/pull/2344
