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

inferno: I'm really confused about this one. Maybe you can help me understand what's going on. Also +Internals>Instrumentation>Memory 

The bug is occurring during loading a dll for a pepper plugin during the initialization of the zygote on linux. The crash is happening deep within the tcmalloc code. The error message itself is weird and confusing "Bad-cast to DefaultSysAllocator from DefaultSysAllocator"

Probably related to  bug 741604 

Ah I just saw that one, thanks :) 

Same root cause as 741604.

ClusterFuzz has detected this issue as fixed in range 485877:486149.

Detailed report: https://clusterfuzz.com/testcase?key=4841370429947904

Fuzzer: inferno_twister
Job Type: linux_ubsan_vptr_content_shell_drt
Platform Id: linux

Crash Type: Bad-cast
Crash Address: 0x7f40bb7d7440
Crash State:
  Bad-cast to DefaultSysAllocator from DefaultSysAllocator
  DefaultSysAllocator::DefaultSysAllocator
  InitSystemAllocators
  
Sanitizer: undefined (UBSAN)

Recommended Security Severity: High

Regressed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_content_shell_drt&range=485795:485869
Fixed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_content_shell_drt&range=485877:486149

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4841370429947904


Additional requirements: Requires HTTP

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.

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