It is not a security issue, but may be valid functional bug. Eric, could you please take a look?

Correct, this is not a security bug.

It is a problem with the fuzz test setup -- need to call base::i18n::InitializeICU() in any test that depends on GURL, since internally it may depend on ICU.

The crash here is occurring because ICU was not initialized.

I think I will create a base helper for all the net fuzzers that always initialize ICU.

Work in progress: https://codereview.chromium.org/1760973002/

FYI, when reviewing any new //net fuzzer we should check that it depends on "net_fuzzer_test_support" to initialize ICU.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/02b4fe56060de5d37e3a2a36afdfdd4944bb544a

commit 02b4fe56060de5d37e3a2a36afdfdd4944bb544a
Author: eroman <eroman@chromium.org>
Date: Fri Mar 04 12:15:16 2016

Initialize ICU before running any of the //net fuzzers.

ICU is used internally by //net through GURL, however needs to be first initialized by calling base::i18n::InitializeICU().

Do this initialization via a static initializer for any //net fuzzer to be safe, since it is not always obvious when this dependency is used.

BUG= 591677 

Review URL: https://codereview.chromium.org/1760973002

Cr-Commit-Position: refs/heads/master@{#379270}

[modify] https://crrev.com/02b4fe56060de5d37e3a2a36afdfdd4944bb544a/net/BUILD.gn
[modify] https://crrev.com/02b4fe56060de5d37e3a2a36afdfdd4944bb544a/net/DEPS
[add] https://crrev.com/02b4fe56060de5d37e3a2a36afdfdd4944bb544a/net/base/fuzzer_test_support.cc
[modify] https://crrev.com/02b4fe56060de5d37e3a2a36afdfdd4944bb544a/net/base/registry_controlled_domains/get_domain_and_registry_fuzzer.cc
[modify] https://crrev.com/02b4fe56060de5d37e3a2a36afdfdd4944bb544a/net/ftp/ftp_directory_listing_fuzzer.cc

ClusterFuzz has detected this issue as fixed in range 379054:379821.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=4801884835020800

Fuzzer: libfuzzer_parse_data_url_fuzzer
Job Type: libfuzzer_chrome_asan
Platform Id: linux

Crash Type: UNKNOWN
Crash Address: 0x03e90000031b
Crash State:
  gsignal
  UIDNAWrapper
  Pointer
  
Regressed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=378811:378884
Fixed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=379054:379821

Minimized Testcase (0.38 Kb): https://cluster-fuzz.appspot.com/download/AMIfv94DHIaCHGuE3zur52mV_reKpC87nfmMM6C4VsjpoqKcDrWlm7q172KBWitFTI3xPoXEsKIhKxEQWHbQrCKQ0LC4f1eZ7CyPLHeeEAsQ24T_cgd9VAoHckebgOEjW5pe2bwoISoOTSf4sL61PHD896ABU87tWg

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.

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