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

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The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/a3b77d560e245ee04cdc254e033ff29e55a7cf86

commit a3b77d560e245ee04cdc254e033ff29e55a7cf86
Author: ahaas <ahaas@chromium.org>
Date: Wed Nov 02 17:06:38 2016

[wasm] Fix br_table in the wasm interpreter to use varuint32.

The wasm interpreter crashed because it interpreted the table of
br_table as a table of uint8, but according to the spec it is a table of
varint32. Therefore the wasm interpreter misinterpreted 0x80 0x00 as 128
and not as 0, which caused a crash.

R=tizer@chromium.org
BUG= chromium:660262 
TEST=cctest/test-run-wasm/RunWasmInterpreted_Regression_660262

Review-Url: https://codereview.chromium.org/2463063002
Cr-Commit-Position: refs/heads/master@{#40708}

[modify] https://crrev.com/a3b77d560e245ee04cdc254e033ff29e55a7cf86/src/wasm/wasm-interpreter.cc
[modify] https://crrev.com/a3b77d560e245ee04cdc254e033ff29e55a7cf86/test/cctest/wasm/test-run-wasm.cc

ClusterFuzz has detected this issue as fixed in range 429549:429574.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=4733719077453824

Fuzzer: afl_v8_wasm_code_fuzzer
Job Type: afl_chrome_asan
Platform Id: linux

Crash Type: Heap-use-after-free READ 8
Crash Address: 0x6250000183f0
Crash State:
  v8::internal::wasm::ThreadImpl::DoBreak
  v8::internal::wasm::ThreadImpl::Execute
  v8::internal::wasm::ThreadImpl::Run
  
Recommended Security Severity: High

Regressed: https://cluster-fuzz.appspot.com/revisions?job=afl_chrome_asan&range=427847:428110
Fixed: https://cluster-fuzz.appspot.com/revisions?job=afl_chrome_asan&range=429549:429574

Minimized Testcase (0.03 Kb): https://cluster-fuzz.appspot.com/download/AMIfv97vBiHY8ZndlXYZOz_6PG6QzaqETJ4dyKGDrKASg8WDohL-E7jRIHpX_PhuSqVV8pVuydpFF8WR1BvSEckSdvHah9zoFUk-DZ-aNeUK5NbOvVq8eH8aOCkjxgpvWyrUA4IFU7FZ__aIxCr4U1zQ2t1x_3VZjg?testcase_id=4733719077453824

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.

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