Findit could not find any suspect, providing results for internal purpose:

Suspected CLs	Findit could not determine the memory tool from the stacktrace. Is it in a new format?

assigning to https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/editing/OWNERS
ojan@/ yosin@ - Could you please check the above issue & help us in finding an owner

Lower to Pri-2 since real world usage of InsertNewlineInQuotedContent is low.

ClusterFuzz has detected this issue as fixed in range 418478:418496.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5812145067655168

Fuzzer: inferno_layout_test_unmodified
Job Type: linux_debug_content_shell_drt
Platform Id: linux

Crash Type: CHECK failure
Crash Address: 
Crash State:
  !endingSelection().isNone() in BreakBlockquoteCommand.cpp
  blink::BreakBlockquoteCommand::doApply
  blink::CompositeEditCommand::applyCommandToComposite
  
Regressed: https://cluster-fuzz.appspot.com/revisions?job=linux_debug_content_shell_drt&range=380105:380146
Fixed: https://cluster-fuzz.appspot.com/revisions?job=linux_debug_content_shell_drt&range=418478:418496

Minimized Testcase (1.13 Kb): https://cluster-fuzz.appspot.com/download/AMIfv97ncLy6qwMQ2g039lhygVFynPalRvrz0c4mTg7Sl25H5QP8UnCs3tuAHwX4s4UUD964Mgd2LU4-uiZjzyE5vpLC2RcRzWZAdr5gBG0NGLuzLH0sVw7qHmtNxmKsgXkbx6ycNBfPKfV0wBxrVgOpyw1r6Qbp9w?testcase_id=5812145067655168

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 is verified as fixed, closing issue.

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