mstarzinger: Can you please take a look? Thanks.

Regression range points to 3ab49f664f6ff3d048f949aacdb178e249cbc3ec. Redruced repro looks as follows ...

var x = new Intl.NumberFormat(); 
x.formatToParts();

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

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I've reproduced the issue locally. Working on a fix now.

Fwiw, this only happens with the recently-staged --harmony-number-format-to-parts.

Submitted a CL with a fix: https://chromium-review.googlesource.com/c/v8/v8/+/668677

This is a test coverage hole. I'll submit a PR to test262 to cover this.

test262 PR: https://github.com/tc39/test262/pull/1226

ClusterFuzz has detected this issue as fixed in range 48037:48038.

Detailed report: https://clusterfuzz.com/testcase?key=5491287963992064

Fuzzer: inferno_js_fuzzer
Job Type: linux_asan_d8_dbg
Platform Id: linux

Crash Type: DCHECK failure
Crash Address: 
Crash State:
  index < length() in builtins-utils.h
  v8::internal::Builtin_Impl_NumberFormatPrototypeFormatToParts
  v8::internal::Builtin_NumberFormatPrototypeFormatToParts
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_asan_d8_dbg&range=47976:47977
Fixed: https://clusterfuzz.com/revisions?job=linux_asan_d8_dbg&range=48037:48038

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5491287963992064

See https://github.com/google/clusterfuzz-tools 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 5491287963992064 is verified as fixed, so closing issue as verified.

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

This was broken by Siggi's https://chromium.googlesource.com/v8/v8/+log/c5295b0d71b2024423dbd5c954acd12eceb8f657..a787c3f9e12d8f392f56d7116dbf1fac09b12123?pretty=fuller&n=10000 and not ClusterFuzz's fault.

Ok i think this is due to Fatal Error stacks changing now, reuploaded testcase in https://clusterfuzz.com/v2/testcase-detail/5927935277268992?noredirect=1.

 Issue 765803  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/f42f51448b3a8938240be78574c7936cab7ff15f

commit f42f51448b3a8938240be78574c7936cab7ff15f
Author: Josh Wolfe <jwolfe@igalia.com>
Date: Mon Sep 18 20:07:23 2017

[intl] fix off-by-1 in NumberFormat formatToParts parameter parsing

R=adamk@chromium.org, mstarzinger@chromium.org

Bug:  v8:5244 ,  chromium:765479 
Cq-Include-Trybots: master.tryserver.v8:v8_linux_noi18n_rel_ng
Change-Id: I684805acc194a93b96d74e3e64834867dce78dee
Reviewed-on: https://chromium-review.googlesource.com/668677
Reviewed-by: Daniel Ehrenberg <littledan@chromium.org>
Commit-Queue: Josh Wolfe <jwolfe@igalia.com>
Cr-Commit-Position: refs/heads/master@{#48069}
[modify] https://crrev.com/f42f51448b3a8938240be78574c7936cab7ff15f/src/builtins/builtins-intl.cc
[add] https://crrev.com/f42f51448b3a8938240be78574c7936cab7ff15f/test/test262/local-tests/test/intl402/NumberFormat/prototype/formatToParts/default-parameter.js

jwolfe: Uh oh! This issue still open and hasn't been updated in the last 14 days. This is a serious vulnerability, and we want to ensure that there's progress. Could you please leave an update with the current status and any potential blockers?

If you're not the right owner for this issue, could you please remove yourself as soon as possible or help us find the right one?

If the issue is fixed or you can't reproduce it, please close the bug. If you've started working on a fix, please set the status to Started.

Thanks for your time! To disable nags, add the Disable-Nags label.

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

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