[PATCH -next v2] kunit: fix uninitialized variables bug in attributes filtering

From: Rae Moar
Date: Thu Aug 03 2023 - 15:37:10 EST


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@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: https://lore.kernel.org/r/202307270610.s0w4NKEn-lkp@xxxxxxxxx/

Signed-off-by: Rae Moar <rmoar@xxxxxxxxxx>
---

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