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Issue metadata

Status: WontFix
Owner:
Closed: Dec 2016
Cc:
EstimatedDays: ----
NextAction: ----
OS: Linux
Pri: 2
Type: Bug



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Integer-overflow in _hb_ot_shape_fallback_spaces

Project Member Reported by ClusterFuzz, Aug 25 2016

Issue description

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=4788735084593152

Fuzzer: inferno_twister
Job Type: linux_ubsan_chrome
Platform Id: linux

Crash Type: Integer-overflow
Crash Address: 
Crash State:
  _hb_ot_shape_fallback_spaces
  hb_ot_shape_internal
  _hb_ot_shape
  
Regressed: https://cluster-fuzz.appspot.com/revisions?job=linux_ubsan_chrome&range=370022:370027

Minimized Testcase (0.05 Kb):
Download: https://cluster-fuzz.appspot.com/download/AMIfv963hM2BTgOfWgIX4DutmHZ4QccMMjA5PU8C5Lutder3scS4kK7kXvUVfA9fW-o7fCxLHIRDkUXxpmzvRefpo-jT4MpMlwygCgvTkkaaxwLDQKwukFk7TMWQo-SafST0UbM4ef2JdlHH0lxWmRiWNj9LEnfpjQ?testcase_id=4788735084593152
<style>* {
    zoom: 190652441;
</style>
K&#x205f;


Issue manually filed by: mmohammad

See https://dev.chromium.org/Home/chromium-security/bugs/reproducing-clusterfuzz-bugs for more information.
 
Owner: drott@chromium.org
Status: Assigned (was: Untriaged)
drott @ could you please look into this.please feel free to re-assigned back if needed. thanks in advance !

Comment 2 by drott@chromium.org, Aug 25 2016

Cc: behdad@chromium.org
Looks like there is another angle to create a giant font using the CSS zoom syntax. We have one way of clamping font sizes now to 10000 on the CSS side where we parse font size values, but we would need to introduce more clamping elsewhere in order to avoid those. Is there a way HarfBuzz could safely bail for too large values, so that we don't have to clamp to somewhat arbitrary values higher up?
The best way might be to move the limit check to exactly when you are creating Skia and HarfBuzz fonts.
Labels: Pri-2
Project Member

Comment 5 by sheriffbot@chromium.org, Nov 22 2016

Labels: -Restrict-View-EditIssue
Removing EditIssue view restrictions from ClusterFuzz filed bugs. If you believe that this issue should still be restricted, please reapply the label.

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

Comment 6 by ClusterFuzz, Dec 22 2016

Status: WontFix (was: Assigned)
ClusterFuzz testcase 4788735084593152 is flaky and no longer reproduces, so closing issue.

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

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