drm/msm/dp: Free resources after unregistering them

[ Upstream commit fa0048a4b1fa7a50c8b0e514f5b428abdf69a6f8 ]

The DP component's unbind operation walks through the submodules to
unregister and clean things up. But if the unbind happens because the DP
controller itself is being removed, all the memory for those submodules
has just been freed.

Change the order of these operations to avoid the many use-after-free
that otherwise happens in this code path.

Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/542166/
Link: https://lore.kernel.org/r/20230612220259.1884381-1-quic_bjorande@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 57b82e5..d16c123 100644 (file)
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -1342,9 +1342,9 @@ static int dp_display_remove(struct platform_device *pdev)
 {
        struct dp_display_private *dp = dev_get_dp_display_private(&pdev->dev);
 
+       component_del(&pdev->dev, &dp_display_comp_ops);
        dp_display_deinit_sub_modules(dp);
 
-       component_del(&pdev->dev, &dp_display_comp_ops);
        platform_set_drvdata(pdev, NULL);
 
        return 0;