kunit: test: Fix the possible memory leak in executor_test

When CONFIG_KUNIT_ALL_TESTS=y, making CONFIG_DEBUG_KMEMLEAK=y and
CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y, the below memory leak is detected.

If kunit_filter_suites() succeeds, not only copy but also filtered_suite
and filtered_suite->test_cases should be freed.

So as Rae suggested, to avoid the suite set never be freed when
KUNIT_ASSERT_EQ() fails and exits after kunit_filter_suites() succeeds,
update kfree_at_end() func to free_suite_set_at_end() to use
kunit_free_suite_set() to free them as kunit_module_exit() and
kunit_run_all_tests() do it. As the second arg got of
free_suite_set_at_end() is a local variable, copy it for free to avoid
wild-memory-access. After applying this patch, the following memory leak
is never detected.

unreferenced object 0xffff8881001de400 (size 1024):
  comm "kunit_try_catch", pid 1396, jiffies 4294720452 (age 932.801s)
  hex dump (first 32 bytes):
    73 75 69 74 65 32 00 00 00 00 00 00 00 00 00 00  suite2..........
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff817db753>] __kmalloc_node_track_caller+0x53/0x150
    [<ffffffff817bd242>] kmemdup+0x22/0x50
    [<ffffffff829e961d>] kunit_filter_suites+0x44d/0xcc0
    [<ffffffff829eb69f>] filter_suites_test+0x12f/0x360
    [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff8881052cd388 (size 192):
  comm "kunit_try_catch", pid 1396, jiffies 4294720452 (age 932.801s)
  hex dump (first 32 bytes):
    a0 85 9e 82 ff ff ff ff 80 cd 7c 84 ff ff ff ff  ..........|.....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff817dbad2>] __kmalloc+0x52/0x150
    [<ffffffff829e9651>] kunit_filter_suites+0x481/0xcc0
    [<ffffffff829eb69f>] filter_suites_test+0x12f/0x360
    [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20

unreferenced object 0xffff888100da8400 (size 1024):
  comm "kunit_try_catch", pid 1398, jiffies 4294720454 (age 781.945s)
  hex dump (first 32 bytes):
    73 75 69 74 65 32 00 00 00 00 00 00 00 00 00 00  suite2..........
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff817db753>] __kmalloc_node_track_caller+0x53/0x150
    [<ffffffff817bd242>] kmemdup+0x22/0x50
    [<ffffffff829e961d>] kunit_filter_suites+0x44d/0xcc0
    [<ffffffff829eb13f>] filter_suites_test_glob_test+0x12f/0x560
    [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888105117878 (size 96):
  comm "kunit_try_catch", pid 1398, jiffies 4294720454 (age 781.945s)
  hex dump (first 32 bytes):
    a0 85 9e 82 ff ff ff ff a0 ac 7c 84 ff ff ff ff  ..........|.....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff817dbad2>] __kmalloc+0x52/0x150
    [<ffffffff829e9651>] kunit_filter_suites+0x481/0xcc0
    [<ffffffff829eb13f>] filter_suites_test_glob_test+0x12f/0x560
    [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888102c31c00 (size 1024):
  comm "kunit_try_catch", pid 1404, jiffies 4294720460 (age 781.948s)
  hex dump (first 32 bytes):
    6e 6f 72 6d 61 6c 5f 73 75 69 74 65 00 00 00 00  normal_suite....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff817db753>] __kmalloc_node_track_caller+0x53/0x150
    [<ffffffff817bd242>] kmemdup+0x22/0x50
    [<ffffffff829ecf17>] kunit_filter_attr_tests+0xf7/0x860
    [<ffffffff829e99ff>] kunit_filter_suites+0x82f/0xcc0
    [<ffffffff829ea975>] filter_attr_test+0x195/0x5f0
    [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff8881052cd250 (size 192):
  comm "kunit_try_catch", pid 1404, jiffies 4294720460 (age 781.948s)
  hex dump (first 32 bytes):
    a0 85 9e 82 ff ff ff ff 00 a9 7c 84 ff ff ff ff  ..........|.....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff817dbad2>] __kmalloc+0x52/0x150
    [<ffffffff829ecfc1>] kunit_filter_attr_tests+0x1a1/0x860
    [<ffffffff829e99ff>] kunit_filter_suites+0x82f/0xcc0
    [<ffffffff829ea975>] filter_attr_test+0x195/0x5f0
    [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888104f4e400 (size 1024):
  comm "kunit_try_catch", pid 1408, jiffies 4294720464 (age 781.944s)
  hex dump (first 32 bytes):
    73 75 69 74 65 00 00 00 00 00 00 00 00 00 00 00  suite...........
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff817db753>] __kmalloc_node_track_caller+0x53/0x150
    [<ffffffff817bd242>] kmemdup+0x22/0x50
    [<ffffffff829ecf17>] kunit_filter_attr_tests+0xf7/0x860
    [<ffffffff829e99ff>] kunit_filter_suites+0x82f/0xcc0
    [<ffffffff829e9fc3>] filter_attr_skip_test+0x133/0x6e0
    [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff8881052cc620 (size 192):
  comm "kunit_try_catch", pid 1408, jiffies 4294720464 (age 781.944s)
  hex dump (first 32 bytes):
    a0 85 9e 82 ff ff ff ff c0 a8 7c 84 ff ff ff ff  ..........|.....
    00 00 00 00 00 00 00 00 02 00 00 00 02 00 00 00  ................
  backtrace:
    [<ffffffff817dbad2>] __kmalloc+0x52/0x150
    [<ffffffff829ecfc1>] kunit_filter_attr_tests+0x1a1/0x860
    [<ffffffff829e99ff>] kunit_filter_suites+0x82f/0xcc0
    [<ffffffff829e9fc3>] filter_attr_skip_test+0x133/0x6e0
    [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20

Fixes: e5857d39 ("kunit: flatten kunit_suite*** to kunit_suite** in .kunit_test_suites")
Fixes: 76066f93 ("kunit: add tests for filtering attributes")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Suggested-by: David Gow <davidgow@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202309142251.uJ8saAZv-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202309270433.wGmFRGjd-lkp@intel.com/Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib/kunit/executor_test.c

@@ -9,7 +9,7 @@
 #include <kunit/test.h>
 #include <kunit/attributes.h>
 
-static void kfree_at_end(struct kunit *test, const void *to_free);
+static void free_suite_set_at_end(struct kunit *test, const void *to_free);
 static struct kunit_suite *alloc_fake_suite(struct kunit *test,
 					    const char *suite_name,
 					    struct kunit_case *test_cases);
@@ -56,7 +56,7 @@ static void filter_suites_test(struct kunit *test)
 	got = kunit_filter_suites(&suite_set, "suite2", NULL, NULL, &err);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
 	KUNIT_ASSERT_EQ(test, err, 0);
-	kfree_at_end(test, got.start);
+	free_suite_set_at_end(test, &got);
 
 	/* Validate we just have suite2 */
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]);
@@ -82,7 +82,7 @@ static void filter_suites_test_glob_test(struct kunit *test)
 	got = kunit_filter_suites(&suite_set, "suite2.test2", NULL, NULL, &err);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
 	KUNIT_ASSERT_EQ(test, err, 0);
-	kfree_at_end(test, got.start);
+	free_suite_set_at_end(test, &got);
 
 	/* Validate we just have suite2 */
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]);
@@ -109,7 +109,7 @@ static void filter_suites_to_empty_test(struct kunit *test)
 
 	got = kunit_filter_suites(&suite_set, "not_found", NULL, NULL, &err);
 	KUNIT_ASSERT_EQ(test, err, 0);
-	kfree_at_end(test, got.start); /* just in case */
+	free_suite_set_at_end(test, &got); /* just in case */
 
 	KUNIT_EXPECT_PTR_EQ_MSG(test, got.start, got.end,
 				"should be empty to indicate no match");
@@ -172,7 +172,7 @@ static void filter_attr_test(struct kunit *test)
 	got = kunit_filter_suites(&suite_set, NULL, filter, NULL, &err);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
 	KUNIT_ASSERT_EQ(test, err, 0);
-	kfree_at_end(test, got.start);
+	free_suite_set_at_end(test, &got);
 
 	/* Validate we just have normal_suite */
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]);
@@ -200,7 +200,7 @@ static void filter_attr_empty_test(struct kunit *test)
 
 	got = kunit_filter_suites(&suite_set, NULL, filter, NULL, &err);
 	KUNIT_ASSERT_EQ(test, err, 0);
-	kfree_at_end(test, got.start); /* just in case */
+	free_suite_set_at_end(test, &got); /* just in case */
 
 	KUNIT_EXPECT_PTR_EQ_MSG(test, got.start, got.end,
 				"should be empty to indicate no match");
@@ -222,7 +222,7 @@ static void filter_attr_skip_test(struct kunit *test)
 	got = kunit_filter_suites(&suite_set, NULL, filter, "skip", &err);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
 	KUNIT_ASSERT_EQ(test, err, 0);
-	kfree_at_end(test, got.start);
+	free_suite_set_at_end(test, &got);
 
 	/* Validate we have both the slow and normal test */
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]->test_cases);
@@ -256,18 +256,26 @@ kunit_test_suites(&executor_test_suite);
 
 /* Test helpers */
 
-/* Use the resource API to register a call to kfree(to_free).
+static void free_suite_set(void *suite_set)
+{
+	kunit_free_suite_set(*(struct kunit_suite_set *)suite_set);
+	kfree(suite_set);
+}
+
+/* Use the resource API to register a call to free_suite_set.
  * Since we never actually use the resource, it's safe to use on const data.
  */
-static void kfree_at_end(struct kunit *test, const void *to_free)
+static void free_suite_set_at_end(struct kunit *test, const void *to_free)
 {
-	/* kfree() handles NULL already, but avoid allocating a no-op cleanup. */
-	if (IS_ERR_OR_NULL(to_free))
+	struct kunit_suite_set *free;
+
+	if (!((struct kunit_suite_set *)to_free)->start)
 		return;
 
-	kunit_add_action(test,
-			(kunit_action_t *)kfree,
-			(void *)to_free);
+	free = kzalloc(sizeof(struct kunit_suite_set), GFP_KERNEL);
+	*free = *(struct kunit_suite_set *)to_free;
+
+	kunit_add_action(test, free_suite_set, (void *)free);
 }
 
 static struct kunit_suite *alloc_fake_suite(struct kunit *test,