Date:   Thu,  3 Aug 2023 19:36:35 +0000
From:   Rae Moar <rmoar@...gle.com>
To:     shuah@...nel.org, davidgow@...gle.com, brendan.higgins@...ux.dev
Cc:     ruanjinjie@...wei.com, linux-kselftest@...r.kernel.org,
        kunit-dev@...glegroups.com, linux-kernel@...r.kernel.org,
        Rae Moar <rmoar@...gle.com>, kernel test robot <lkp@...el.com>,
        Dan Carpenter <dan.carpenter@...aro.org>
Subject: [PATCH -next v2] kunit: fix uninitialized variables bug in attributes filtering

Fix smatch warnings regarding uninitialized variables in the filtering
patch of the new KUnit Attributes feature.

Fixes: 529534e8cba3 ("kunit: Add ability to filter attributes")

Reported-by: kernel test robot <lkp@...el.com>
Reported-by: Dan Carpenter <dan.carpenter@...aro.org>
Closes: https://lore.kernel.org/r/202307270610.s0w4NKEn-lkp@intel.com/

Signed-off-by: Rae Moar <rmoar@...gle.com>
---

Change since v1:
- Changed initialization of filtered to be {NULL, NULL} at the start and
  only updated when ready to return.
- Remove unnecessary +1 in memory allocation for parsed_filters in
  executor test.

Note that this is rebased on top of the recent fix:
("kunit: fix possible memory leak in kunit_filter_suites()").

 lib/kunit/attributes.c    | 40 +++++++++++++++++----------------------
 lib/kunit/executor.c      | 18 +++++++++++-------
 lib/kunit/executor_test.c |  2 +-
 3 files changed, 29 insertions(+), 31 deletions(-)

diff --git a/lib/kunit/attributes.c b/lib/kunit/attributes.c
index d37c40c0ce4f..5e3034b6be99 100644
--- a/lib/kunit/attributes.c
+++ b/lib/kunit/attributes.c
@@ -102,7 +102,7 @@ static int int_filter(long val, const char *op, int input, int *err)
 static int attr_enum_filter(void *attr, const char *input, int *err,
 		const char * const str_list[], int max)
 {
-	int i, j, input_int;
+	int i, j, input_int = -1;
 	long test_val = (long)attr;
 	const char *input_val = NULL;
 
@@ -124,7 +124,7 @@ static int attr_enum_filter(void *attr, const char *input, int *err,
 			input_int = j;
 	}
 
-	if (!input_int) {
+	if (input_int < 0) {
 		*err = -EINVAL;
 		pr_err("kunit executor: invalid filter input: %s\n", input);
 		return false;
@@ -186,8 +186,10 @@ static void *attr_module_get(void *test_or_suite, bool is_test)
 	// Suites get their module attribute from their first test_case
 	if (test)
 		return ((void *) test->module_name);
-	else
+	else if (kunit_suite_num_test_cases(suite) > 0)
 		return ((void *) suite->test_cases[0].module_name);
+	else
+		return (void *) "";
 }
 
 /* List of all Test Attributes */
@@ -221,7 +223,7 @@ const char *kunit_attr_filter_name(struct kunit_attr_filter filter)
 void kunit_print_attr(void *test_or_suite, bool is_test, unsigned int test_level)
 {
 	int i;
-	bool to_free;
+	bool to_free = false;
 	void *attr;
 	const char *attr_name, *attr_str;
 	struct kunit_suite *suite = is_test ? NULL : test_or_suite;
@@ -255,7 +257,7 @@ void kunit_print_attr(void *test_or_suite, bool is_test, unsigned int test_level
 
 int kunit_get_filter_count(char *input)
 {
-	int i, comma_index, count = 0;
+	int i, comma_index = 0, count = 0;
 
 	for (i = 0; input[i]; i++) {
 		if (input[i] == ',') {
@@ -272,7 +274,7 @@ int kunit_get_filter_count(char *input)
 struct kunit_attr_filter kunit_next_attr_filter(char **filters, int *err)
 {
 	struct kunit_attr_filter filter = {};
-	int i, j, comma_index, new_start_index;
+	int i, j, comma_index = 0, new_start_index = 0;
 	int op_index = -1, attr_index = -1;
 	char op;
 	char *input = *filters;
@@ -316,7 +318,7 @@ struct kunit_attr_filter kunit_next_attr_filter(char **filters, int *err)
 		filter.attr = &kunit_attr_list[attr_index];
 	}
 
-	if (comma_index) {
+	if (comma_index > 0) {
 		input[comma_index] = '\0';
 		filter.input = input + op_index;
 		input = input + new_start_index;
@@ -356,31 +358,22 @@ struct kunit_suite *kunit_filter_attr_tests(const struct kunit_suite *const suit
 
 	/* Save filtering result on default value */
 	default_result = filter.attr->filter(filter.attr->attr_default, filter.input, err);
-	if (*err) {
-		kfree(copy);
-		kfree(filtered);
-		return NULL;
-	}
+	if (*err)
+		goto err;
 
 	/* Save suite attribute value and filtering result on that value */
 	suite_val = filter.attr->get_attr((void *)suite, false);
 	suite_result = filter.attr->filter(suite_val, filter.input, err);
-	if (*err) {
-		kfree(copy);
-		kfree(filtered);
-		return NULL;
-	}
+	if (*err)
+		goto err;
 
 	/* For each test case, save test case if passes filtering. */
 	kunit_suite_for_each_test_case(suite, test_case) {
 		test_val = filter.attr->get_attr((void *) test_case, true);
 		test_result = filter.attr->filter(filter.attr->get_attr(test_case, true),
 				filter.input, err);
-		if (*err) {
-			kfree(copy);
-			kfree(filtered);
-			return NULL;
-		}
+		if (*err)
+			goto err;
 
 		/*
 		 * If attribute value of test case is set, filter on that value.
@@ -406,7 +399,8 @@ struct kunit_suite *kunit_filter_attr_tests(const struct kunit_suite *const suit
 		}
 	}
 
-	if (n == 0) {
+err:
+	if (n == 0 || *err) {
 		kfree(copy);
 		kfree(filtered);
 		return NULL;
diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
index 481901d245d0..dc295150c4e5 100644
--- a/lib/kunit/executor.c
+++ b/lib/kunit/executor.c
@@ -127,19 +127,18 @@ static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
 {
 	int i, j, k;
 	int filter_count = 0;
-	struct kunit_suite **copy, *filtered_suite, *new_filtered_suite;
-	struct suite_set filtered;
+	struct kunit_suite **copy, **copy_start, *filtered_suite, *new_filtered_suite;
+	struct suite_set filtered = {NULL, NULL};
 	struct kunit_glob_filter parsed_glob;
-	struct kunit_attr_filter *parsed_filters;
+	struct kunit_attr_filter *parsed_filters = NULL;
 
 	const size_t max = suite_set->end - suite_set->start;
 
 	copy = kmalloc_array(max, sizeof(*filtered.start), GFP_KERNEL);
-	filtered.start = copy;
 	if (!copy) { /* won't be able to run anything, return an empty set */
-		filtered.end = copy;
 		return filtered;
 	}
+	copy_start = copy;
 
 	if (filter_glob)
 		kunit_parse_glob_filter(&parsed_glob, filter_glob);
@@ -147,7 +146,11 @@ static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
 	/* Parse attribute filters */
 	if (filters) {
 		filter_count = kunit_get_filter_count(filters);
-		parsed_filters = kcalloc(filter_count + 1, sizeof(*parsed_filters), GFP_KERNEL);
+		parsed_filters = kcalloc(filter_count, sizeof(*parsed_filters), GFP_KERNEL);
+		if (!parsed_filters) {
+			kfree(copy);
+			return filtered;
+		}
 		for (j = 0; j < filter_count; j++)
 			parsed_filters[j] = kunit_next_attr_filter(&filters, err);
 		if (*err)
@@ -166,7 +169,7 @@ static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
 				goto err;
 			}
 		}
-		if (filter_count) {
+		if (filter_count > 0 && parsed_filters != NULL) {
 			for (k = 0; k < filter_count; k++) {
 				new_filtered_suite = kunit_filter_attr_tests(filtered_suite,
 						parsed_filters[k], filter_action, err);
@@ -195,6 +198,7 @@ static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
 
 		*copy++ = filtered_suite;
 	}
+	filtered.start = copy_start;
 	filtered.end = copy;
 
 err:
diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c
index 01280cb8d451..3e0a1c99cb4e 100644
--- a/lib/kunit/executor_test.c
+++ b/lib/kunit/executor_test.c
@@ -119,7 +119,7 @@ static void parse_filter_attr_test(struct kunit *test)
 	filter_count = kunit_get_filter_count(filters);
 	KUNIT_EXPECT_EQ(test, filter_count, 2);
 
-	parsed_filters = kunit_kcalloc(test, filter_count + 1, sizeof(*parsed_filters),
+	parsed_filters = kunit_kcalloc(test, filter_count, sizeof(*parsed_filters),
 			GFP_KERNEL);
 	for (j = 0; j < filter_count; j++) {
 		parsed_filters[j] = kunit_next_attr_filter(&filters, &err);

base-commit: 3bffe185ad11e408903d2782727877388d08d94e
-- 
2.41.0.585.gd2178a4bd4-goog

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