8360664: Null pointer dereference in src/hotspot/share/prims/jvmtiTagMap.cpp in IterateOverHeapObjectClosure::do_object()

[savoptik]

Hi all,

This pull request contains a backport of commit [e9a43416](https://github.com/openjdk/jdk/commit/e9a434165a6ec07cde0429c7f9823bbc5dab7857) from the [openjdk/jdk](https://git.openjdk.org/jdk) repository.

The commit being backported was authored by Artem Semenov on 7 Jul 2025 and was reviewed by Serguei Spitsyn, Alex Menkov and Chris Plummer.

This patch adds an assert that demonstrates that NULL cannot be passed to this function. This change will simplify code analysis during bug hunting and investigation.

Thanks!

---

Progress

• Change must not contain extraneous whitespace
• JDK-8360664 needs maintainer approval
• Commit message must refer to an issue

Issue

• JDK-8360664: Null pointer dereference in src/hotspot/share/prims/jvmtiTagMap.cpp in IterateOverHeapObjectClosure::do_object() (Bug - P4 - Approved)

Reviewing

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Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk25u.git pull/19/head:pull/19
$ git checkout pull/19

Update a local copy of the PR:
$ git checkout pull/19
$ git pull https://git.openjdk.org/jdk25u.git pull/19/head

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Checkout this PR locally:
$ git pr checkout 19

View PR using the GUI difftool:
$ git pr show -t 19

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Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back asemenov! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@savoptik This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8360664: Null pointer dereference in src/hotspot/share/prims/jvmtiTagMap.cpp in IterateOverHeapObjectClosure::do_object()

Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Artem Semenov <[email protected]>.

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been no new commits pushed to the master branch. If another commit should be pushed before you perform the /integrate command, your PR will be automatically rebased. If you prefer to avoid any potential automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[openjdk]

This backport pull request has now been updated with issue and summary from the original commit.

[openjdk]

⚠️ @savoptik This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[mlbridge]

Webrevs

• 00: Full (54656ddf)

[savoptik]

/integrate

[openjdk]

Going to push as commit 7145ba1.
Since your change was applied there have been 37 commits pushed to the master branch:

• 987af5a: Merge
• e8f2cd8: 8347052: Update java man page documentation to reflect current state of the UseNUMA flag
• e599ee4: 8361827: [TESTBUG] serviceability/HeapDump/UnmountedVThreadNativeMethodAtTop.java throws OutOfMemoryError
• ... and 34 more: https://git.openjdk.org/jdk25u/compare/db6230991b3e7ea5ee068c22c1f4c538e2c10074...master

Your commit was automatically rebased without conflicts.

[openjdk]

@savoptik Pushed as commit 7145ba1.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.