In resource_test_insert_resource(), the pointer is used in error
message after kfree(). This is user-after-free. To fix this, we need
to call kunit_add_action_or_reset() to schedule memory freeing after
usage. But kunit_add_action_or_reset() itself may fail and free the
memory. So, its return value should be checked and abort the test for
failure. Then, we found that other usage of
kunit_add_action_or_reset() in resource_test_region_intersects() needs
to be fixed too. We fix all these user-after-free bugs in this patch.
Fixes: 99185c10d5d9 ("resource, kunit: add test case for region_intersects()")
Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reported-by: Kees Bakker <kees@xxxxxxxxxxxx>
Closes: https://lore.kernel.org/lkml/87ldzaotcg.fsf@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
kernel/resource_kunit.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/kernel/resource_kunit.c b/kernel/resource_kunit.c
index 42d2d8d20f5d..b8ef75b99eb2 100644
--- a/kernel/resource_kunit.c
+++ b/kernel/resource_kunit.c
@@ -169,6 +169,8 @@ static void resource_test_intersection(struct kunit *test)
#define RES_TEST_RAM3_SIZE SZ_1M
#define RES_TEST_TOTAL_SIZE ((RES_TEST_WIN1_OFFSET + RES_TEST_WIN1_SIZE))
+KUNIT_DEFINE_ACTION_WRAPPER(kfree_wrapper, kfree, const void *);
+
static void remove_free_resource(void *ctx)
{
struct resource *res = (struct resource *)ctx;
@@ -177,6 +179,14 @@ static void remove_free_resource(void *ctx)
kfree(res);
}
+static void resource_test_add_action_or_abort(
+ struct kunit *test, void (*action)(void *), void *ctx)
+{
+ KUNIT_ASSERT_EQ_MSG(test, 0,
+ kunit_add_action_or_reset(test, action, ctx),
+ "Fail to add action");
+}
+
static void resource_test_request_region(struct kunit *test, struct resource *parent,
resource_size_t start, resource_size_t size,
const char *name, unsigned long flags)
@@ -185,7 +195,7 @@ static void resource_test_request_region(struct kunit *test, struct resource *pa
res = __request_region(parent, start, size, name, flags);
KUNIT_ASSERT_NOT_NULL(test, res);
- kunit_add_action_or_reset(test, remove_free_resource, res);
+ resource_test_add_action_or_abort(test, remove_free_resource, res);
}
static void resource_test_insert_resource(struct kunit *test, struct resource *parent,
@@ -202,11 +212,11 @@ static void resource_test_insert_resource(struct kunit *test, struct resource *p
res->end = start + size - 1;
res->flags = flags;
if (insert_resource(parent, res)) {
- kfree(res);
+ resource_test_add_action_or_abort(test, kfree_wrapper, res);
KUNIT_FAIL_AND_ABORT(test, "Fail to insert resource %pR\n", res);
}
- kunit_add_action_or_reset(test, remove_free_resource, res);
+ resource_test_add_action_or_abort(test, remove_free_resource, res);
}
static void resource_test_region_intersects(struct kunit *test)
@@ -220,7 +230,7 @@ static void resource_test_region_intersects(struct kunit *test)
"test resources");
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
start = parent->start;
- kunit_add_action_or_reset(test, remove_free_resource, parent);
+ resource_test_add_action_or_abort(test, remove_free_resource, parent);
resource_test_request_region(test, parent, start + RES_TEST_RAM0_OFFSET,
RES_TEST_RAM0_SIZE, "Test System RAM 0", flags);
--
2.39.2
