It looks to me like the culprit CL is: https://chromium.googlesource.com/v8/v8/+/f0523e30467789cbb3689b8023a207d3b5c4873c

clemensh@ -- can you please help triage this? Thanks.

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/5e7428b5b13ca50f77a027409eaf0b0d99dfaf72

commit 5e7428b5b13ca50f77a027409eaf0b0d99dfaf72
Author: ahaas <ahaas@chromium.org>
Date: Thu Sep 01 09:52:23 2016

[wasm] Read global names only if their name length is valid.

BUG= chromium:642987 
R=titzer@chromium.org
TEST=module-decoder-unittest.cc:GlobalWithInvalidNameLength

Review-Url: https://codereview.chromium.org/2301873002
Cr-Commit-Position: refs/heads/master@{#39071}

[modify] https://crrev.com/5e7428b5b13ca50f77a027409eaf0b0d99dfaf72/src/wasm/module-decoder.cc
[modify] https://crrev.com/5e7428b5b13ca50f77a027409eaf0b0d99dfaf72/test/unittests/wasm/module-decoder-unittest.cc

This issue is a security regression. If you are not able to fix this quickly, please revert the change that introduced it.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

ClusterFuzz has detected this issue as fixed in range 415984:416149.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5738904961679360

Fuzzer: libfuzzer_v8_wasm_fuzzer
Job Type: libfuzzer_chrome_asan
Platform Id: linux

Crash Type: Heap-buffer-overflow READ 1
Crash Address: 0x60a00000347b
Crash State:
  unibrow::Utf8::Validate
  DecodeGlobalInModule
  DecodeModule
  
Recommended Security Severity: Medium

Regressed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=415621:415679
Fixed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=415984:416149

Minimized Testcase (0.03 Kb): https://cluster-fuzz.appspot.com/download/AMIfv96HM2W7MgB9PLsb7nkYl0tM_xUh8Nw8FgmIQgwQFNtTqJp57Zv6qAf7KtqdMbeTMbIBkONTZtZ3mRGq8f-C-SmC7WlAJ2ulqAQu1VxICvhjVQIZN2bdUaMKMf9w3mKjC_kBr4qwBcptOr6dtsKeSbCsbGwdzw?testcase_id=5738904961679360

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz testcase is verified as fixed, closing issue.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.

Not fixed, more testcases coming.

Friendly ping, this is currently a Beta-blocker and needs to get fixed and merged as soon as feasible, as M54 is going to beta this Thursday 9/8

I am still waiting for the test cases promised in #11. To me this issue seems to be fixed. Moreover, this is a WebAssembly issue, and WebAssembly is hidden behind a flag at the moment. I don't think this issue should be a Beta-blocker.

I've checked other crashes on ClusterFuzz, there is a similar crash. As discussed via hangouts, I've filed it separately ( bug 644182 ), since there is another reproducer and that requires another fix.

Closing this issue as the initial crash is not reproducible now.

This bug has been closed for more than 14 weeks. Removing security view restrictions.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot