Added extra validation for invalid characters as well as tests.

include/aws/common/ipc_util.h

@@ -31,4 +31,4 @@ void aws_ipc_util_instance_lock_release(struct aws_ipc_util_instance_lock *insta
 
 AWS_EXTERN_C_END
 
-#endif /* #ifndef AWS_COMMON_IPC_UTIL_H */
+#endif /* AWS_COMMON_IPC_UTIL_H */

source/posix/ipc_util.c

@@ -20,6 +20,17 @@ struct aws_ipc_util_instance_lock {
 struct aws_ipc_util_instance_lock *aws_ipc_util_instance_lock_try_acquire(
     struct aws_allocator *allocator,
     struct aws_byte_cursor instance_nonce) {
+
+    /* validate we don't have a directory slash. */
+    struct aws_byte_cursor to_find = aws_byte_cursor_from_c_str("/");
+    struct aws_byte_cursor found;
+    AWS_ZERO_STRUCT(found);
+    if (aws_byte_cursor_find_exact(&instance_nonce, &to_find, &found) != AWS_OP_ERR &&
+        aws_last_error() != AWS_ERROR_STRING_MATCH_NOT_FOUND) {
+        aws_raise_error(AWS_ERROR_INVALID_ARGUMENT);
+        return NULL;
+    }
+
     /*
      * The unix standard says /tmp has to be there and be writable. However, while it may be tempting to just use the
      * /tmp/ directory, it often has the sticky bit set which would prevent a subprocess from being able to call open

source/windows/ipc_util.c

@@ -17,6 +17,17 @@ struct aws_ipc_util_instance_lock {
 struct aws_ipc_util_instance_lock *aws_ipc_util_instance_lock_try_acquire(
     struct aws_allocator *allocator,
     struct aws_byte_cursor instance_nonce) {
+
+    /* validate we don't have a directory slash. */
+    struct aws_byte_cursor to_find = aws_byte_cursor_from_c_str("\\");
+    struct aws_byte_cursor found;
+    AWS_ZERO_STRUCT(found);
+    if (aws_byte_cursor_find_exact(&instance_nonce, &to_find, &found) != AWS_OP_ERR &&
+        aws_last_error() != AWS_ERROR_STRING_MATCH_NOT_FOUND) {
+        aws_raise_error(AWS_ERROR_INVALID_ARGUMENT);
+        return NULL;
+    }
+
     struct aws_byte_cursor path_prefix = aws_byte_cursor_from_c_str("Global/");
     struct aws_byte_buf nonce_buf;
     aws_byte_buf_init_copy_from_cursor(&nonce_buf, allocator, path_prefix);

tests/CMakeLists.txt

@@ -525,6 +525,7 @@ add_test_case(test_instance_lock_works_in_proc)
 add_test_case(test_instance_lock_works_cross_proc)
 #this one is here for use by test_instance_lock_works_cross_proc
 add_test_case(instance_lock_mp_test_runner)
+add_test_case(test_instance_lock_invalid_nonce_fails)
 
 
 generate_test_driver(${PROJECT_NAME}-tests)

tests/io_util_tests.c

@@ -69,11 +69,11 @@ static int s_test_instance_lock_works_cross_proc(struct aws_allocator *allocator
 
     /* Invoke the test runner in a new process for ease so cmake automatically does the work for us. */
     struct aws_run_command_options command_options = {
-#ifdef __WIN32
+#ifdef _WIN32
         .command = "aws-c-common-tests instance_lock_mp_test_runner",
 #else
         .command = "./aws-c-common-tests instance_lock_mp_test_runner",
-#endif
+#endif /* _WIN32 */
     };
 
     struct aws_run_command_result result;
@@ -97,3 +97,22 @@ static int s_test_instance_lock_works_cross_proc(struct aws_allocator *allocator
     return AWS_OP_SUCCESS;
 }
 AWS_TEST_CASE(test_instance_lock_works_cross_proc, s_test_instance_lock_works_cross_proc)
+
+static int s_test_instance_lock_invalid_nonce(struct aws_allocator *allocator, void *ctx) {
+    (void)ctx;
+    aws_common_library_init(allocator);
+#ifdef _WIN32
+    struct aws_byte_cursor lock_nonce = aws_byte_cursor_from_c_str("invalid\\lock_nonce");
+#else
+    struct aws_byte_cursor lock_nonce = aws_byte_cursor_from_c_str("invalid/lock_nonce");
+#endif /* _WIN32 */
+
+    struct aws_ipc_util_instance_lock *instance_lock = aws_ipc_util_instance_lock_try_acquire(allocator, lock_nonce);
+    ASSERT_NULL(instance_lock);
+    ASSERT_INT_EQUALS(AWS_ERROR_INVALID_ARGUMENT, aws_last_error());
+
+    aws_common_library_clean_up();
+
+    return AWS_OP_SUCCESS;
+}
+AWS_TEST_CASE(test_instance_lock_invalid_nonce_fails, s_test_instance_lock_invalid_nonce)