Add some test cases for flow involving global variables and captured variables

Author: joefarebrother

python/ql/test/library-tests/dataflow/global-or-captured-vars/test.expected

@@ -0,0 +1,4 @@
+argumentToEnsureNotTaintedNotMarkedAsSpurious
+untaintedArgumentToEnsureTaintedNotMarkedAsMissing
+testFailures
+failures

python/ql/test/library-tests/dataflow/global-or-captured-vars/test.py

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+import threading 
+import time
+
+# Test 1
+# TP - Flow is tracked through a global variable
+foo1 = None
+
+def bar1():
+    time.sleep(1)
+    ensure_tainted(foo1) # $tainted
+
+# The intent of these tests is to test how dataflow is handled through shared state accessed by different threads; 
+# but the presense or absense of the actual call to start a thread does not affect the results (there is no special modelling for Thread)
+# threading.Thread(target=bar).start() 
+
+foo1 = TAINTED_STRING
+
+# Test 2
+# FN - Flow is *not* tracked through an access path on a global variable
+foo2 = []
+
+def bar2():
+    time.sleep(1)
+    ensure_tainted(foo2[0]) # $MISSING:tainted
+
+threading.Thread(target=bar2).start()
+
+foo2.append(TAINTED_STRING)
+
+# Test 3
+# FN - Flow is not found even when there is a direct call
+foo3 = []
+
+def bar3():
+    time.sleep(1)
+    ensure_tainted(foo2[0]) # $MISSING:tainted
+
+foo3.append(TAINTED_STRING)
+bar3()
+
+# Tast 4
+# TP - Sanity check: Flow is found through a ListElement directly without a call
+foo4 = []
+foo4.append(TAINTED_STRING)
+ensure_tainted(foo4[0]) # $tainted
+
+# Test 5
+# FN - Flow is *not* tracked through a shared captured but non-global variable
+def test5():
+    foo5 = None 
+
+    def bar5():
+        time.sleep(1)
+        ensure_tainted(foo5) # $MISSING:tainted
+
+    threading.Thread(target=bar5).start() # Only the presense of this thread call makes this an FN rather than a TN
+
+    foo5 = TAINTED_STRING
+
+ # Test 6
+ # TP - Flow is tracked through a shared captured but non-global variable with a direct call
+def test6():
+    foo6 = []
+
+    def bar6():
+        time.sleep(1)
+        ensure_tainted(foo[0]) # $tainted
+
+    foo6.append(TAINTED_STRING)
+    bar6()
+
+
+# Test 7
+# FN - Flow is *not* found through an access path on a global variable that's also used as a parameter
+# We'd like to cover this case in order to be able to cover this CVE: https://github.com/github/codeql-python-CVE-coverage/issues/3176
+
+foo7 = []
+
+def bar7():
+    time.sleep(1)
+    ensure_tainted(foo7[0]) # $MISSING: tainted
+
+def baz7(loc_foo):
+    loc_foo.append(TAINTED_STRING)
+
+threading.Thread(target=bar7).start()
+
+baz7(foo7)

python/ql/test/library-tests/dataflow/global-or-captured-vars/test.ql

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+import python
+import experimental.meta.InlineTaintTest
+import MakeInlineTaintTest<TestTaintTrackingConfig>