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

If this doesn't affect a release branch, or has not been properly classified for severity, please update the Security_Impact or Security_Severity labels, and remove the ReleaseBlock label. To disable this altogether, apply ReleaseBlock-NA.

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

reed@, is it possible this is caused by your latest change https://chromium-review.googlesource.com/c/548536/?  

Feel free to re-assign

The following revision refers to this bug:
  https://skia.googlesource.com/skia/+/8b9566a257312f1cbd447f0cfdbb2cfb349f3c26

commit 8b9566a257312f1cbd447f0cfdbb2cfb349f3c26
Author: Florin Malita <fmalita@chromium.org>
Date: Wed Jul 05 17:14:14 2017

Disallow burst context instantiation for non-invertible CTMs

Similar to SkShaderBase::makeContext(), catch this condition and bail
early.

BUG= chromium:738682 

Change-Id: I4c7a2036bed8ab8699023c4f8f3bc2161de0c41d
Reviewed-on: https://skia-review.googlesource.com/21521
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>

[modify] https://crrev.com/8b9566a257312f1cbd447f0cfdbb2cfb349f3c26/src/shaders/SkShader.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f53b0375775430158df440550f3d6712a0fd205e

commit f53b0375775430158df440550f3d6712a0fd205e
Author: skia-deps-roller@chromium.org <skia-deps-roller@chromium.org>
Date: Thu Jul 06 01:05:40 2017

Roll src/third_party/skia/ 7aad8cc2f..b1de5f9f2 (12 commits)

https://skia.googlesource.com/skia.git/+log/7aad8cc2ff7a..b1de5f9f2737

$ git log 7aad8cc2f..b1de5f9f2 --date=short --no-merges --format='%ad %ae %s'
2017-07-01 halcanary SkDocument:  consolidate trimBox code
2017-07-05 bsalomon Use RGBA rather than N32 for GPU tests
2017-07-05 egdaniel Add basic metal build files for backend
2017-07-05 ethannicholas rewrote GrAlphaThresholdFragmentProcessor in sksl
2017-07-05 reed add srgb gamma colorfilters ... faster and more accurate than using SkTableColorFilter
2017-07-05 halcanary SkPDF: GradientShaderPatterns use one hashmap not two.
2017-07-04 reed add --csv option to nanobench
2017-07-05 scroggo Remove CodecSrc::kIndex8_Always_DstColorType
2017-07-05 reed doh -- fix capitalization
2017-07-05 halcanary SkPDF: Refactor PDFShader to use ShTHashMap<>
2017-07-05 csmartdalton Revert "Indicate texel buffer support in Vulkan"
2017-07-05 fmalita Disallow burst context instantiation for non-invertible CTMs

Created with:
  roll-dep src/third_party/skia
BUG= 738682 


Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, see:
http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls


CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
TBR=csmartdalton@chromium.org

Change-Id: I8ee265dfee142d09a51fb712aa5d4a99327f0abb
Reviewed-on: https://chromium-review.googlesource.com/560666
Reviewed-by: Skia Deps Roller <skia-deps-roller@chromium.org>
Commit-Queue: Skia Deps Roller <skia-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#484432}
[modify] https://crrev.com/f53b0375775430158df440550f3d6712a0fd205e/DEPS

ClusterFuzz has detected this issue as fixed in range 484368:484445.

Detailed report: https://clusterfuzz.com/testcase?key=6554381964279808

Fuzzer: inferno_canvas_wrecker
Job Type: linux_msan_chrome
Platform Id: linux

Crash Type: Use-of-uninitialized-value
Crash Address: 
Crash State:
  SkShaderBase::Context::Context
  SkGradientShaderBase::GradientShaderBase4fContext::GradientShaderBase4fContext
  SkLinearGradient::LinearGradient4fContext::LinearGradient4fContext
  
Sanitizer: memory (MSAN)

Recommended Security Severity: Medium

Regressed: https://clusterfuzz.com/revisions?job=linux_msan_chrome&range=482701:482716
Fixed: https://clusterfuzz.com/revisions?job=linux_msan_chrome&range=484368:484445

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=6554381964279808


See https://dev.chromium.org/Home/chromium-security/bugs/reproducing-clusterfuzz-bugs 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 6554381964279808 is verified as fixed, so 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