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Issue 806540 link

Starred by 2 users

Issue metadata

Status: Verified
Owner:
Last visit 16 days ago
Closed: Feb 2018
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Linux
Pri: 3
Type: Bug



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Null-dereference READ during FormatBlock command

Project Member Reported by ClusterFuzz, Jan 27 2018

Issue description

Detailed report: https://clusterfuzz.com/testcase?key=6020288274497536

Fuzzer: inferno_layout_test_unmodified
Job Type: linux_msan_content_shell_drt
Platform Id: linux

Crash Type: Null-dereference READ
Crash Address: 0x000000000010
Crash State:
  blink::PositionIteratorAlgorithm<blink::EditingAlgorithm<blink::NodeTraversal> >
  blink::MostBackwardCaretPosition
  blink::CanonicalPositionOf
  
Sanitizer: memory (MSAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_msan_content_shell_drt&range=518240:518474

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=6020288274497536

Issue filed automatically.

See https://github.com/google/clusterfuzz-tools for more information.
 
Components: Blink>Editing
Cc: brajkumar@chromium.org
Labels: -Type-Bug M-64 Test-Predator-Wrong Type-Bug-Regression
Owner: xiaoche...@chromium.org
Status: Assigned (was: Untriaged)
Predator and CL could not provide any possible suspects.

Using Code Search for the file, "VisibleUnits.cpp" and observed there was some recent changes for the below file.

Suspect CL: https://chromium.googlesource.com/chromium/src/+/e65d6289cd28260dcd05078ffd49ebdd8e8dbf77

xiaochengh@ -- Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Thanks!
Components: -Blink>Editing Blink>Editing>Command
Labels: -Pri-1 -Type-Bug-Regression Pri-3 Type-Bug
Owner: ----
Status: Available (was: Assigned)
Summary: Null-dereference READ during FormatBlock command (was: Null-dereference READ in blink::PositionIteratorAlgorithm<blink::EditingAlgorithm<blink::NodeTraversal> >)
The CL doesn't contain any behavioral changes. It's pure code moving.

Applying P3/Available due to low real world usage of FormatBlock command.

Also removing the regression label because editing command is a big source of crashes due to some fundamental design issue, and crashes there are not regressions in most cases.
Owner: tanvir.r...@samsung.com
Simplfied case: 
<head>
<script>
function start() {
document.designMode='on';
document.execCommand('selectall');
document.execCommand('FormatBlock', false, '<pre>');
}
setTimeout(start);
</script>
</head>
<body>
<input>
<div style="display:inline-block;" contenteditable></div><canvas></body>
Project Member

Comment 6 by ClusterFuzz, Feb 13 2018

ClusterFuzz has detected this issue as fixed in range 536251:536255.

Detailed report: https://clusterfuzz.com/testcase?key=6020288274497536

Fuzzer: inferno_layout_test_unmodified
Job Type: linux_msan_content_shell_drt
Platform Id: linux

Crash Type: Null-dereference READ
Crash Address: 0x000000000010
Crash State:
  blink::PositionIteratorAlgorithm<blink::EditingAlgorithm<blink::NodeTraversal> >
  blink::MostBackwardCaretPosition
  blink::CanonicalPositionOf
  
Sanitizer: memory (MSAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_msan_content_shell_drt&range=518240:518474
Fixed: https://clusterfuzz.com/revisions?job=linux_msan_content_shell_drt&range=536251:536255

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=6020288274497536

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.
Project Member

Comment 7 by ClusterFuzz, Feb 13 2018

Labels: ClusterFuzz-Verified
Status: Verified (was: Available)
ClusterFuzz testcase 6020288274497536 is verified as fixed, so closing issue as verified.

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

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