Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
New issues: - [High] Newly added mock device is freed on test abort while scheduler workqueues are still running. Pre-existing issues: - [High] NULL pointer dereference in test suite exit functions if drm_mock_sched_new() aborts during initialization. -- commit 87ec4ea74ea7485f78bc8e603289f73cd4461eb5 Author: Shixiong Ou <[email protected]> drm/sched: Create a fake device for KUnit tests This commit creates a dummy device using kunit_device_register() for the mock scheduler in KUnit tests. This prevents a NULL pointer dereference in the drm_sched_job trace event which relies on sched->dev. > diff --git a/drivers/gpu/drm/scheduler/tests/mock_scheduler.c > b/drivers/gpu/drm/scheduler/tests/mock_scheduler.c > index 8e9ae7d980eb2..2dfa3efef2100 100644 > --- a/drivers/gpu/drm/scheduler/tests/mock_scheduler.c > +++ b/drivers/gpu/drm/scheduler/tests/mock_scheduler.c [ ... ] > @@ -297,11 +300,19 @@ struct drm_mock_scheduler *drm_mock_sched_new(struct > kunit *test, long timeout) > .name = "drm-mock-scheduler", > }; > struct drm_mock_scheduler *sched; > + struct device *dev; > + char name[64]; > int ret; > > sched = kunit_kzalloc(test, sizeof(*sched), GFP_KERNEL); > KUNIT_ASSERT_NOT_NULL(test, sched); > > + snprintf(name, sizeof(name), "%s-%u", args.name, instance++); > + dev = kunit_device_register(test, name); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev); [Severity: High] This is a pre-existing issue, but does this assertion expose a crash in the test suite's exit functions? If kunit_device_register() fails in drm_mock_sched_new(), the KUNIT_ASSERT_NOT_ERR_OR_NULL macro aborts the initialization sequence. Control returns to the KUnit framework without test->priv being initialized. When the framework subsequently runs the suite's exit function (drm_sched_basic_exit()), it extracts test->priv and passes it to drm_mock_sched_fini(), which unconditionally dereferences the NULL pointer. Could this lead to a kernel panic during test failure rather than cleanly reporting the error? > + > + args.dev = dev; > + > ret = drm_sched_init(&sched->base, &args); > KUNIT_ASSERT_EQ(test, ret, 0); [Severity: High] Could tying the mock device to the KUnit test lifecycle cause a use-after-free if the test aborts? The device allocated with kunit_device_register() is automatically freed when the KUnit test thread exits. However, drm_sched_init() spawns background tasks (scheduler workqueues) that hold references to this device. If a subsequent test assertion fails (e.g., KUNIT_ASSERT_FALSE in drm_sched_test_credits()), the test aborts, skipping the manual drm_mock_sched_fini() cleanup. KUnit will automatically free the mock device, but the background tasks remain active and may attempt to access the freed device memory. Should the scheduler cleanup be registered as a deferred KUnit action to ensure the workqueues are stopped before the device is freed? -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=1
