Looks like not a security issue (null-deref), but since we've just started to fuzz hunspell, I speculatively mark it as a Low Severity to keep it safe.

Looks like we are hitting this crash very quickly, would be nice to get it fixed and continue fuzzing with better coverage.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=4698042800537600

Fuzzer: libfuzzer_hunspell_fuzzer
Job Type: libfuzzer_chrome_asan
Platform Id: linux

Crash Type: UNKNOWN READ
Crash Address: 0x000000000091
Crash State:
  SuggestMgr::leftcommonsubstring
  SuggestMgr::ngsuggest
  Hunspell::suggest
  

Minimized Testcase (0.19 Kb): https://cluster-fuzz.appspot.com/download/AMIfv94IzgJfuwDLUFDKESqvBjGWsaKnxlVWzFJQflAuzfqwB7dzqePKelmQukQeEMQdGksDHEVnrhC82S0QWteitSOM3sChUKH5rN3Cg9nSofcn2DK7kkGdkodi0MUYM2LbcbGQk9s9nnnQywTymX6P8GXUBmstmw?testcase_id=4698042800537600

Filer: mmoroz

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md for more information.

ClusterFuzz has detected this testcase as flaky and is unable to reproduce it in the original crash revision. Skipping fixed testing check and marking it as potentially fixed.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=6645225435168768

Fuzzer: libfuzzer_hunspell_fuzzer
Job Type: libfuzzer_chrome_asan
Platform Id: linux

Crash Type: UNKNOWN READ
Crash Address: 0x000000000091
Crash State:
  SuggestMgr::leftcommonsubstring
  SuggestMgr::ngsuggest
  Hunspell::suggest
  
Regressed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=401846:401864

Minimized Testcase (0.03 Kb): https://cluster-fuzz.appspot.com/download/AMIfv94DbYaxDUptpjqk3aYrHuR_7HtXSiWcEBAG5PbBVm7LZPB9hvPk5juMstAFwQIRyhFefvE-1z-Umj91iZttqlzKeeJvh5XdEfo9XS-u00S8unI1CkS_T-WnnZIR98d_bY28t-2leJtWA_seLhj6w_JvDNHtdg?testcase_id=6645225435168768

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz has detected this testcase as flaky and is unable to reproduce it in the original crash revision. Skipping fixed testing check and marking it as potentially fixed.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=4698042800537600

Fuzzer: libfuzzer_hunspell_fuzzer
Job Type: libfuzzer_chrome_asan
Platform Id: linux

Crash Type: UNKNOWN READ
Crash Address: 0x000000000091
Crash State:
  SuggestMgr::leftcommonsubstring
  SuggestMgr::ngsuggest
  Hunspell::suggest
  
Regressed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=401846:401864

Minimized Testcase (0.19 Kb): https://cluster-fuzz.appspot.com/download/AMIfv94IzgJfuwDLUFDKESqvBjGWsaKnxlVWzFJQflAuzfqwB7dzqePKelmQukQeEMQdGksDHEVnrhC82S0QWteitSOM3sChUKH5rN3Cg9nSofcn2DK7kkGdkodi0MUYM2LbcbGQk9s9nnnQywTymX6P8GXUBmstmw?testcase_id=4698042800537600

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5849359910699008

Fuzzer: libfuzzer_hunspell_fuzzer
Job Type: libfuzzer_chrome_asan
Platform Id: linux

Crash Type: UNKNOWN READ
Crash Address: 0x000000000091
Crash State:
  SuggestMgr::leftcommonsubstring
  SuggestMgr::ngsuggest
  Hunspell::suggest
  

Minimized Testcase (0.07 Kb): https://cluster-fuzz.appspot.com/download/AMIfv94ywQx0ZiiZoMc3GRJGX0f1E4a0fHr0y4I5WcMskmh5lsW7hsm6cDB6V11ZcURo37zB7j8y7JqtUJDJ_TvfliIZH68RnCsXZe6LLxhtvJvaekZB4UKlggqDUdMA6EM6vDzcfyqjNh5DmJcEPgQWgrG_ixxszA?testcase_id=5849359910699008

Issue manually filed by: mmoroz

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md for more information.

Any chance to fix this? Fuzzer almost always hits this crash and literally does nothing for the last 4 months.

I'm not familiar with hunspell's codebase, but after a quick look it seems that global `csconv` pointer (https://cs.chromium.org/chromium/src/third_party/hunspell/src/hunspell/suggestmgr.hxx?sq=package:chromium&type=cs&rcl=1478665324&l=45)

is not initialized in some cases:

https://cs.chromium.org/chromium/src/third_party/hunspell/src/hunspell/suggestmgr.cxx?q=file:src/third_party/hunspell/src/hunspell/suggestmgr.cxx+csconv&sq=package:chromium&dr=C&l=128

but then it can be used anyway:

https://cs.chromium.org/chromium/src/third_party/hunspell/src/hunspell/suggestmgr.cxx?sq=package:chromium&type=cs&l=1998



Not sure if it is a bug or an incorrect usage (we do not initialize something?), but it shouldn't take much time for people familiar with hunspell.

I'd recommend to use some of recent CF reports (e.g. https://cluster-fuzz.appspot.com/v2/testcase-detail/5849359910699008) to reproduce.

Thanks in advance!

ClusterFuzz has detected this issue as fixed in range 438154:438196.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5849359910699008

Fuzzer: libfuzzer_hunspell_fuzzer
Job Type: libfuzzer_chrome_asan
Platform Id: linux

Crash Type: UNKNOWN READ
Crash Address: 0x000000000091
Crash State:
  SuggestMgr::leftcommonsubstring
  SuggestMgr::ngsuggest
  Hunspell::suggest
  
Regressed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=401846:401864
Fixed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_asan&range=438154:438196

Minimized Testcase (0.07 Kb): https://cluster-fuzz.appspot.com/download/AMIfv94ywQx0ZiiZoMc3GRJGX0f1E4a0fHr0y4I5WcMskmh5lsW7hsm6cDB6V11ZcURo37zB7j8y7JqtUJDJ_TvfliIZH68RnCsXZe6LLxhtvJvaekZB4UKlggqDUdMA6EM6vDzcfyqjNh5DmJcEPgQWgrG_ixxszA?testcase_id=5849359910699008

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md 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 5849359910699008 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