Merge pull request github#6839 from geoffw0/toctoufp

CPP: Add test cases for cpp/toctou-race-condition

Author: geoffw0

cpp/ql/test/query-tests/Security/CWE/CWE-367/semmle/TOCTOUFilesystemRace.expected

@@ -5,9 +5,13 @@
 | test2.cpp:130:7:130:11 | call to fopen | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:130:13:130:16 | path | filename | test2.cpp:128:21:128:27 | buf_ptr | checked |
 | test2.cpp:157:7:157:10 | call to open | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:157:12:157:15 | path | filename | test2.cpp:155:6:155:9 | call to stat | checked |
 | test2.cpp:170:7:170:10 | call to open | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:170:12:170:15 | path | filename | test2.cpp:168:6:168:10 | call to lstat | checked |
-| test2.cpp:245:3:245:7 | call to chmod | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:245:9:245:12 | path | filename | test2.cpp:238:6:238:10 | call to fopen | checked |
-| test2.cpp:277:7:277:11 | call to fopen | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:277:13:277:16 | path | filename | test2.cpp:275:6:275:11 | call to access | checked |
-| test2.cpp:303:7:303:11 | call to fopen | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:303:13:303:16 | path | filename | test2.cpp:301:7:301:12 | call to access | checked |
-| test2.cpp:317:7:317:11 | call to fopen | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:317:13:317:16 | path | filename | test2.cpp:313:6:313:11 | call to access | checked |
-| test2.cpp:348:3:348:7 | call to chmod | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:348:9:348:12 | path | filename | test2.cpp:341:6:341:10 | call to fopen | checked |
-| test2.cpp:356:3:356:7 | call to chmod | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:356:9:356:13 | path2 | filename | test2.cpp:354:7:354:12 | call to rename | checked |
+| test2.cpp:209:7:209:10 | call to open | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:209:12:209:15 | path | filename | test2.cpp:207:6:207:9 | call to stat | checked |
+| test2.cpp:228:8:228:11 | call to open | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:228:13:228:16 | path | filename | test2.cpp:224:6:224:9 | call to stat | checked |
+| test2.cpp:228:8:228:11 | call to open | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:228:13:228:16 | path | filename | test2.cpp:226:7:226:9 | buf | checked |
+| test2.cpp:249:6:249:10 | call to fopen | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:249:12:249:15 | path | filename | test2.cpp:244:6:244:9 | call to stat | checked |
+| test2.cpp:297:3:297:7 | call to chmod | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:297:9:297:12 | path | filename | test2.cpp:290:6:290:10 | call to fopen | checked |
+| test2.cpp:329:7:329:11 | call to fopen | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:329:13:329:16 | path | filename | test2.cpp:327:6:327:11 | call to access | checked |
+| test2.cpp:355:7:355:11 | call to fopen | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:355:13:355:16 | path | filename | test2.cpp:353:7:353:12 | call to access | checked |
+| test2.cpp:369:7:369:11 | call to fopen | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:369:13:369:16 | path | filename | test2.cpp:365:6:365:11 | call to access | checked |
+| test2.cpp:400:3:400:7 | call to chmod | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:400:9:400:12 | path | filename | test2.cpp:393:6:393:10 | call to fopen | checked |
+| test2.cpp:408:3:408:7 | call to chmod | The $@ being operated upon was previously $@, but the underlying file may have been changed since then. | test2.cpp:408:9:408:13 | path2 | filename | test2.cpp:406:7:406:12 | call to rename | checked |

cpp/ql/test/query-tests/Security/CWE/CWE-367/semmle/test2.cpp

@@ -199,6 +199,58 @@ void test2_10(int dir, const char *path, int arg)
 	// ...
 }
 
+void test2_11(const char *path, int arg)
+{
+	stat_data buf;
+	int f;
+
+	if (stat(path, &buf))
+	{
+		f = open(path, arg); // GOOD (here stat is just a redundant check that the file exists / path is valid, confirmed by the return value of open) [FALSE POSITIVE]
+		if (f == -1)
+		{
+			// handle error
+		}
+
+		// ...
+	}
+}
+
+void test2_12(const char *path, int arg)
+{
+	stat_data buf;
+	int f;
+
+	if (stat(path, &buf))
+	{
+		if (buf.foo == 11) // check a property of the file
+		{
+			f = open(path, arg); // BAD
+			if (f == -1)
+			{
+				// handle error
+			}
+		}
+
+		// ...
+	}
+}
+
+void test2_13(const char *path, int arg)
+{
+	stat_data buf;
+	FILE *f;
+
+	if (stat(path, &buf)) // check the file does *not* exist
+	{
+		return;
+	}
+
+	f = fopen(path, "wt"); // BAD
+
+	// ...
+}
+
 // --- open -> stat ---
 
 void test3_1(const char *path, int arg)