kunit: Fix possible memory leak in kunit_filter_suites()

If the outer layer for loop is iterated more than once and it fails not
in the first iteration, the filtered_suite and filtered_suite->test_cases
allocated in the last kunit_filter_attr_tests() in last inner for loop
is leaked.

So add a new free_filtered_suite err label and free the filtered_suite
and filtered_suite->test_cases so far. And change kmalloc_array of copy
to kcalloc to Clear the copy to make the kfree safe.

Fixes: 529534e ("kunit: Add ability to filter attributes")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib/kunit/executor.c

@@ -157,10 +157,11 @@ kunit_filter_suites(const struct kunit_suite_set *suite_set,
 	struct kunit_suite_set filtered = {NULL, NULL};
 	struct kunit_glob_filter parsed_glob;
 	struct kunit_attr_filter *parsed_filters = NULL;
+	struct kunit_suite * const *suites;
 
 	const size_t max = suite_set->end - suite_set->start;
 
-	copy = kmalloc_array(max, sizeof(*filtered.start), GFP_KERNEL);
+	copy = kcalloc(max, sizeof(*filtered.start), GFP_KERNEL);
 	if (!copy) { /* won't be able to run anything, return an empty set */
 		return filtered;
 	}
@@ -195,7 +196,7 @@ kunit_filter_suites(const struct kunit_suite_set *suite_set,
 					parsed_glob.test_glob);
 			if (IS_ERR(filtered_suite)) {
 				*err = PTR_ERR(filtered_suite);
-				goto free_parsed_filters;
+				goto free_filtered_suite;
 			}
 		}
 		if (filter_count > 0 && parsed_filters != NULL) {
@@ -212,11 +213,11 @@ kunit_filter_suites(const struct kunit_suite_set *suite_set,
 				filtered_suite = new_filtered_suite;
 
 				if (*err)
-					goto free_parsed_filters;
+					goto free_filtered_suite;
 
 				if (IS_ERR(filtered_suite)) {
 					*err = PTR_ERR(filtered_suite);
-					goto free_parsed_filters;
+					goto free_filtered_suite;
 				}
 				if (!filtered_suite)
 					break;
@@ -231,6 +232,14 @@ kunit_filter_suites(const struct kunit_suite_set *suite_set,
 	filtered.start = copy_start;
 	filtered.end = copy;
 
+free_filtered_suite:
+	if (*err) {
+		for (suites = copy_start; suites < copy; suites++) {
+			kfree((*suites)->test_cases);
+			kfree(*suites);
+		}
+	}
+
 free_parsed_filters:
 	if (filter_count)
 		kfree(parsed_filters);