drm/vc4: tests: Fix UAF in the mock helpers

The VC4 mock helpers allocate the CRTC, encoders and connectors using a
call to kunit_kzalloc(), but the DRM device they are attache to survives
for longer than the test itself which leads to use-after-frees reported
by KASAN.

Switch to drmm_kzalloc to tie the lifetime of these objects to the main
DRM device.

Fixes: f759f5b53f1c ("drm/vc4: tests: Introduce a mocking infrastructure")
Reported-by: Linux Kernel Functional Testing <[email protected]>
Closes: https://lore.kernel.org/all/CA+G9fYvJA2HGqzR9LGgq63v0SKaUejHAE6f7+z9cwWN-ourJ_g@mail.gmail.com/
Tested-by: Anders Roxell <[email protected]>
Reviewed-by: Maíra Canal <[email protected]>
Signed-off-by: Maxime Ripard <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

diff --git a/drivers/gpu/drm/vc4/tests/vc4_mock_crtc.c b/drivers/gpu/drm/vc4/tests/vc4_mock_crtc.c
index 5d12d7beef0eb30099b2dd2a1d8894cfa11ed9bf..ade3309ae042f1fba55c55c64b110b983abaa8df 100644 (file)
--- a/drivers/gpu/drm/vc4/tests/vc4_mock_crtc.c
+++ b/drivers/gpu/drm/vc4/tests/vc4_mock_crtc.c
@@ -26,7 +26,7 @@ struct vc4_dummy_crtc *vc4_mock_pv(struct kunit *test,
        struct vc4_crtc *vc4_crtc;
        int ret;
 
-       dummy_crtc = kunit_kzalloc(test, sizeof(*dummy_crtc), GFP_KERNEL);
+       dummy_crtc = drmm_kzalloc(drm, sizeof(*dummy_crtc), GFP_KERNEL);
        KUNIT_ASSERT_NOT_NULL(test, dummy_crtc);
 
        vc4_crtc = &dummy_crtc->crtc;

diff --git a/drivers/gpu/drm/vc4/tests/vc4_mock_output.c b/drivers/gpu/drm/vc4/tests/vc4_mock_output.c
index 6e11fcc9ef45e0647aa19d7fe53866a6ac6f3a3a..e70d7c3076acf168782c48301f3b3dfb9be21f22 100644 (file)
--- a/drivers/gpu/drm/vc4/tests/vc4_mock_output.c
+++ b/drivers/gpu/drm/vc4/tests/vc4_mock_output.c
@@ -32,7 +32,7 @@ struct vc4_dummy_output *vc4_dummy_output(struct kunit *test,
        struct drm_encoder *enc;
        int ret;
 
-       dummy_output = kunit_kzalloc(test, sizeof(*dummy_output), GFP_KERNEL);
+       dummy_output = drmm_kzalloc(drm, sizeof(*dummy_output), GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dummy_output);
        dummy_output->encoder.type = vc4_encoder_type;