Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues: - [High] This problem wasn't introduced by this patch, but there is a Use-After-Free vulnerability on the error path of `rk3066_hdmi_bind()`. If `rk3066_hdmi_register()` fails, the code jumps to `err_disable_hclk`, skipping the encoder cleanup label `err_cleanup_hdmi`. Since the DRM encoder was added to the DRM device's list during `drm_encoder_init()` but is not removed, and the `hdmi` struct containing the encoder is freed by devres upon bind failure, the DRM core retains a dangling pointer. This will cause a Use-After-Free when the DRM core later iterates over the encoder list or during teardown. -- --- Patch [1]: [PATCH v2] drm/rockchip: rk3066_hdmi: convert to devm_drm_bridge_alloc() API --- commit bdad67e77f8f693946bd674b1a40ce7af3ce54c3 Author: Hüseyin BIYIK <[email protected]> drm/rockchip: rk3066_hdmi: convert to devm_drm_bridge_alloc() API This commit converts the rk3066_hdmi driver to use devm_drm_bridge_alloc() for allocating DRM bridges. This conversion was missed during the initial conversion of all bridges to the new API. > diff --git a/drivers/gpu/drm/rockchip/rk3066_hdmi.c > b/drivers/gpu/drm/rockchip/rk3066_hdmi.c > index f28d6a883e099..39c65ee07caac 100644 > --- a/drivers/gpu/drm/rockchip/rk3066_hdmi.c > +++ b/drivers/gpu/drm/rockchip/rk3066_hdmi.c [ ... ] > @@ -747,9 +746,10 @@ static int rk3066_hdmi_bind(struct device *dev, struct > device *master, > int irq; > int ret; > > - hdmi = devm_kzalloc(dev, sizeof(*hdmi), GFP_KERNEL); > - if (!hdmi) > - return -ENOMEM; > + hdmi = devm_drm_bridge_alloc(dev, struct rk3066_hdmi, bridge, > + &rk3066_hdmi_bridge_funcs); > + if (IS_ERR(hdmi)) > + return PTR_ERR(hdmi); [Severity: High] This isn't a bug introduced by this patch, but while reviewing the allocation of the hdmi struct in rk3066_hdmi_bind() inside drivers/gpu/drm/rockchip/rk3066_hdmi.c, I noticed a potential use-after-free on the error path. If rk3066_hdmi_register() fails after drm_encoder_init() has been called, the error path in rk3066_hdmi_bind() jumps to err_disable_hclk: ret = rk3066_hdmi_register(drm, hdmi); if (ret) goto err_disable_hclk; This bypasses the err_cleanup_hdmi label which destroys the encoder: err_cleanup_hdmi: hdmi->encoder.encoder.funcs->destroy(&hdmi->encoder.encoder); err_disable_hclk: clk_disable_unprepare(hdmi->hclk); Since the encoder was added to the DRM device's internal lists during drm_encoder_init(), and the devm-allocated hdmi struct will be freed when rk3066_hdmi_bind() returns an error, does this leave a dangling pointer in the DRM core that will cause a use-after-free when the list is iterated or torn down? > > hdmi->dev = dev; > hdmi->drm_dev = drm; -- Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=1
