C++: Another test.

cpp/ql/test/query-tests/Security/CWE/CWE-119/semmle/tests/BadlyBoundedWrite.expected

@@ -1,2 +1,4 @@
+| tests.cpp:1056:2:1056:8 | call to strncpy | This 'call to strncpy' operation is limited to 63 bytes but the destination is only -64 bytes. |
+| tests.cpp:1057:2:1057:8 | call to strncpy | This 'call to strncpy' operation is limited to 131 bytes but the destination is only -64 bytes. |
 | var_size_struct.cpp:73:3:73:9 | call to strncpy | This 'call to strncpy' operation is limited to 1025 bytes but the destination is only 1024 bytes. |
 | var_size_struct.cpp:103:3:103:9 | call to strncpy | This 'call to strncpy' operation is limited to 129 bytes but the destination is only 128 bytes. |

cpp/ql/test/query-tests/Security/CWE/CWE-119/semmle/tests/OverflowBuffer.expected

@@ -88,6 +88,10 @@
 | tests.cpp:1001:2:1001:9 | access to array | This array indexing operation accesses a negative index -1 on the $@. | tests.cpp:981:6:981:8 | arr | array |
 | tests.cpp:1009:2:1009:9 | access to array | This array indexing operation accesses a negative index -1 on the $@. | tests.cpp:981:6:981:8 | arr | array |
 | tests.cpp:1031:2:1031:7 | call to memset | This 'memset' operation accesses 130 bytes but the $@ is only 120 bytes. | tests.cpp:1020:12:1020:15 | arr1 | destination buffer |
+| tests.cpp:1051:2:1051:7 | call to memset | This 'memset' operation accesses 64 bytes but the $@ is only -64 bytes. | tests.cpp:1041:8:1041:14 | buffer2 | destination buffer |
+| tests.cpp:1052:2:1052:7 | call to memset | This 'memset' operation accesses 132 bytes but the $@ is only -64 bytes. | tests.cpp:1041:8:1041:14 | buffer2 | destination buffer |
+| tests.cpp:1056:2:1056:8 | call to strncpy | This 'strncpy' operation may access 63 bytes but the $@ is only -64 bytes. | tests.cpp:1041:8:1041:14 | buffer2 | destination buffer |
+| tests.cpp:1057:2:1057:8 | call to strncpy | This 'strncpy' operation may access 131 bytes but the $@ is only -64 bytes. | tests.cpp:1041:8:1041:14 | buffer2 | destination buffer |
 | tests_restrict.c:12:2:12:7 | call to memcpy | This 'memcpy' operation accesses 2 bytes but the $@ is only 1 byte. | tests_restrict.c:7:6:7:13 | smallbuf | source buffer |
 | unions.cpp:26:2:26:7 | call to memset | This 'memset' operation accesses 200 bytes but the $@ is only 100 bytes. | unions.cpp:21:10:21:11 | mu | destination buffer |
 | unions.cpp:30:2:30:7 | call to memset | This 'memset' operation accesses 200 bytes but the $@ is only 100 bytes. | unions.cpp:15:7:15:11 | small | destination buffer |

cpp/ql/test/query-tests/Security/CWE/CWE-119/semmle/tests/OverflowStatic.expected

@@ -5,4 +5,6 @@
 | tests.cpp:245:42:245:42 | 6 | Potential buffer-overflow: 'global_array_5' has size 5 not 6. |
 | tests.cpp:351:2:351:14 | access to array | Potential buffer-overflow: 'charArray' has size 10 but 'charArray[10]' may be accessed here. |
 | tests.cpp:352:17:352:29 | access to array | Potential buffer-overflow: 'charArray' has size 10 but 'charArray[10]' may be accessed here. |
+| tests.cpp:1056:26:1056:47 | ... - ... | Potential buffer-overflow: 'buffer2' has size -64 not 63. |
+| tests.cpp:1057:26:1057:39 | ... - ... | Potential buffer-overflow: 'buffer2' has size -64 not 131. |
 | var_size_struct.cpp:103:39:103:41 | 129 | Potential buffer-overflow: 'str' has size 128 not 129. |

cpp/ql/test/query-tests/Security/CWE/CWE-119/semmle/tests/UnboundedWrite.expected

@@ -27,8 +27,8 @@ edges
 | main.cpp:9:29:9:32 | *argv | tests_restrict.c:15:41:15:44 | *argv | provenance |  |
 | main.cpp:9:29:9:32 | tests_restrict_main output argument | main.cpp:10:20:10:23 | **argv | provenance |  |
 | main.cpp:9:29:9:32 | tests_restrict_main output argument | main.cpp:10:20:10:23 | *argv | provenance |  |
-| main.cpp:10:20:10:23 | **argv | tests.cpp:1034:32:1034:35 | **argv | provenance |  |
-| main.cpp:10:20:10:23 | *argv | tests.cpp:1034:32:1034:35 | *argv | provenance |  |
+| main.cpp:10:20:10:23 | **argv | tests.cpp:1060:32:1060:35 | **argv | provenance |  |
+| main.cpp:10:20:10:23 | *argv | tests.cpp:1060:32:1060:35 | *argv | provenance |  |
 | overflowdestination.cpp:23:45:23:48 | **argv | overflowdestination.cpp:23:45:23:48 | **argv | provenance |  |
 | overflowdestination.cpp:23:45:23:48 | **argv | overflowdestination.cpp:23:45:23:48 | *argv | provenance |  |
 | test_buffer_overrun.cpp:32:46:32:49 | **argv | test_buffer_overrun.cpp:32:46:32:49 | **argv | provenance |  |
@@ -41,12 +41,12 @@ edges
 | tests.cpp:649:14:649:14 | *s [*home] | tests.cpp:649:14:649:19 | *home | provenance |  |
 | tests.cpp:649:14:649:14 | *s [*home] | tests.cpp:649:16:649:19 | *home | provenance |  |
 | tests.cpp:649:16:649:19 | *home | tests.cpp:649:14:649:19 | *home | provenance |  |
-| tests.cpp:1034:32:1034:35 | **argv | tests.cpp:1059:9:1059:15 | *access to array | provenance |  |
-| tests.cpp:1034:32:1034:35 | **argv | tests.cpp:1060:9:1060:15 | *access to array | provenance |  |
-| tests.cpp:1034:32:1034:35 | *argv | tests.cpp:1059:9:1059:15 | *access to array | provenance |  |
-| tests.cpp:1034:32:1034:35 | *argv | tests.cpp:1060:9:1060:15 | *access to array | provenance |  |
-| tests.cpp:1059:9:1059:15 | *access to array | tests.cpp:634:19:634:24 | *source | provenance |  |
-| tests.cpp:1060:9:1060:15 | *access to array | tests.cpp:643:19:643:24 | *source | provenance |  |
+| tests.cpp:1060:32:1060:35 | **argv | tests.cpp:1085:9:1085:15 | *access to array | provenance |  |
+| tests.cpp:1060:32:1060:35 | **argv | tests.cpp:1086:9:1086:15 | *access to array | provenance |  |
+| tests.cpp:1060:32:1060:35 | *argv | tests.cpp:1085:9:1085:15 | *access to array | provenance |  |
+| tests.cpp:1060:32:1060:35 | *argv | tests.cpp:1086:9:1086:15 | *access to array | provenance |  |
+| tests.cpp:1085:9:1085:15 | *access to array | tests.cpp:634:19:634:24 | *source | provenance |  |
+| tests.cpp:1086:9:1086:15 | *access to array | tests.cpp:643:19:643:24 | *source | provenance |  |
 | tests_restrict.c:15:41:15:44 | **argv | tests_restrict.c:15:41:15:44 | **argv | provenance |  |
 | tests_restrict.c:15:41:15:44 | *argv | tests_restrict.c:15:41:15:44 | *argv | provenance |  |
 nodes
@@ -80,10 +80,10 @@ nodes
 | tests.cpp:649:14:649:14 | *s [*home] | semmle.label | *s [*home] |
 | tests.cpp:649:14:649:19 | *home | semmle.label | *home |
 | tests.cpp:649:16:649:19 | *home | semmle.label | *home |
-| tests.cpp:1034:32:1034:35 | **argv | semmle.label | **argv |
-| tests.cpp:1034:32:1034:35 | *argv | semmle.label | *argv |
-| tests.cpp:1059:9:1059:15 | *access to array | semmle.label | *access to array |
-| tests.cpp:1060:9:1060:15 | *access to array | semmle.label | *access to array |
+| tests.cpp:1060:32:1060:35 | **argv | semmle.label | **argv |
+| tests.cpp:1060:32:1060:35 | *argv | semmle.label | *argv |
+| tests.cpp:1085:9:1085:15 | *access to array | semmle.label | *access to array |
+| tests.cpp:1086:9:1086:15 | *access to array | semmle.label | *access to array |
 | tests_restrict.c:15:41:15:44 | **argv | semmle.label | **argv |
 | tests_restrict.c:15:41:15:44 | **argv | semmle.label | **argv |
 | tests_restrict.c:15:41:15:44 | *argv | semmle.label | *argv |

cpp/ql/test/query-tests/Security/CWE/CWE-119/semmle/tests/tests.cpp

@@ -1031,6 +1031,32 @@ void test29() {
 	memset(ptr->arr1, 0, sizeof(ptr->arr1) + sizeof(ptr->arr2) + 10); // BAD
 }
 
+struct UnionStruct {
+	int a;
+	union {
+		char buffer1[64];
+		int b;
+	};
+	union {
+		char buffer2[64];
+		int c;
+	};
+};
+
+void test30() {
+	UnionStruct us;
+
+	memset(us.buffer1, 0, sizeof(us.buffer1)); // GOOD
+	memset(us.buffer1, 0, sizeof(us)); // BAD [NOT DETECTED]
+	memset(us.buffer2, 0, sizeof(us.buffer2)); // GOOD [FALSE POSITIVE]
+	memset(us.buffer2, 0, sizeof(us)); // BAD
+
+	strncpy(us.buffer1, "", sizeof(us.buffer1) - 1); // GOOD
+	strncpy(us.buffer1, "", sizeof(us) - 1); // BAD [NOT DETECTED]
+	strncpy(us.buffer2, "", sizeof(us.buffer2) - 1); // GOOD [FALSE POSITIVE]
+	strncpy(us.buffer2, "", sizeof(us) - 1); // BAD
+}
+
 int tests_main(int argc, char *argv[])
 {
 	long long arr17[19];
@@ -1062,6 +1088,7 @@ int tests_main(int argc, char *argv[])
 	test27(argc);
 	test28();
 	test29();
+	test30();
 
 	return 0;
 }