Make find_main_crash uworker safe (#4403)

Author: jonathanmetzman

src/clusterfuzz/_internal/bot/tasks/utasks/fuzz_task.py

@@ -23,6 +23,7 @@
 from typing import Any
 from typing import Dict
 from typing import List
+from typing import Optional
 
 from google.cloud import ndb
 
@@ -313,7 +314,8 @@ def to_proto(self):
     return crash
 
 
-def find_main_crash(crashes: List[Crash], full_fuzzer_name: str,
+def find_main_crash(crashes: List[Crash],
+                    fuzz_target: Optional[data_types.FuzzTarget],
                     test_timeout: int, upload_urls: UploadUrlCollection):
   """Find the first reproducible crash or the first valid crash. And return the
     crash and the one_time_crasher_flag."""
@@ -331,7 +333,6 @@ def find_main_crash(crashes: List[Crash], full_fuzzer_name: str,
     # security flag and crash state generated from re-running testcase in
     # test_for_reproducibility. Minimize task will later update the new crash
     # type and crash state parameters.
-    fuzz_target = data_handler.get_fuzz_target(full_fuzzer_name)
     if testcase_manager.test_for_reproducibility(
         fuzz_target,
         crash.file_path,
@@ -364,13 +365,8 @@ def __init__(self, crashes: List[Crash], context,
       assert crashes[0].security_flag == c.security_flag
 
     self.crashes = crashes
-    if context.fuzz_target:
-      fully_qualified_fuzzer_name = context.fuzz_target.fully_qualified_name()
-    else:
-      fully_qualified_fuzzer_name = context.fuzzer_name
-
     self.main_crash, self.one_time_crasher_flag = find_main_crash(
-        crashes, fully_qualified_fuzzer_name, context.test_timeout, upload_urls)
+        crashes, context.fuzz_target, context.test_timeout, upload_urls)
 
     self.newly_created_testcase = None
 

src/clusterfuzz/_internal/tests/core/bot/tasks/utasks/fuzz_task_test.py

@@ -501,7 +501,7 @@ def test_no_existing_testcase(self):
 
     self.assertTrue(fuzz_task._should_create_testcase(group, None))
     self.mock.find_main_crash.assert_called_once_with(
-        self.crashes, 'test', self.context.test_timeout, upload_urls)
+        self.crashes, None, self.context.test_timeout, upload_urls)
 
     self.assertEqual(self.crashes[0], group.main_crash)
 
@@ -515,7 +515,7 @@ def test_has_existing_reproducible_testcase(self):
 
     self.assertEqual(self.crashes[0].gestures, group.main_crash.gestures)
     self.mock.find_main_crash.assert_called_once_with(
-        self.crashes, 'test', self.context.test_timeout, upload_urls)
+        self.crashes, None, self.context.test_timeout, upload_urls)
     # TODO(metzman): Replace group in calls to _should_create_testcase with a
     # proto group.
     self.assertFalse(
@@ -530,7 +530,7 @@ def test_reproducible_crash(self):
 
     self.assertEqual(self.crashes[0].gestures, group.main_crash.gestures)
     self.mock.find_main_crash.assert_called_once_with(
-        self.crashes, 'test', self.context.test_timeout, upload_urls)
+        self.crashes, None, self.context.test_timeout, upload_urls)
     self.assertTrue(
         fuzz_task._should_create_testcase(group, self.unreproducible_testcase))
     self.assertFalse(group.one_time_crasher_flag)
@@ -548,7 +548,7 @@ def test_has_existing_unreproducible_testcase(self):
 
     self.assertEqual(self.crashes[0].gestures, group.main_crash.gestures)
     self.mock.find_main_crash.assert_called_once_with(
-        self.crashes, 'test', self.context.test_timeout, upload_urls)
+        self.crashes, None, self.context.test_timeout, upload_urls)
     self.assertTrue(group.one_time_crasher_flag)