On Sat, Mar 08, 2025 at 02:48:39PM +0000, Qasim Ijaz wrote:
> _dpu_encoder_trigger_start dereferences "struct dpu_encoder_phys *phys"
> before the sanity checks which can lead to a NULL pointer dereference if
> phys is NULL.
>
> Fix this by reordering the dereference after the sanity checks.
>
> Signed-off-by: Qasim Ijaz <qasde...@gmail.com>
> Fixes: 8144d17a81d9 ("drm/msm/dpu: Skip trigger flush and start for CWB")
Your SoB should be the last tag. Fixes comes before it.
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 0eed93a4d056..ba8b2a163232 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -1667,8 +1667,6 @@ static void _dpu_encoder_trigger_flush(struct
> drm_encoder *drm_enc,
> */
> static void _dpu_encoder_trigger_start(struct dpu_encoder_phys *phys)
> {
> - struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(phys->parent);
> -
> if (!phys) {
> DPU_ERROR("invalid argument(s)\n");
> return;
> @@ -1679,6 +1677,8 @@ static void _dpu_encoder_trigger_start(struct
> dpu_encoder_phys *phys)
> return;
> }
>
> + struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(phys->parent);
> +
I'm not a fan of having variable defs in the middle of the code. Please
keep the def at the top and assign it here.
> if (phys->parent->encoder_type == DRM_MODE_ENCODER_VIRTUAL &&
> dpu_enc->cwb_mask) {
> DPU_DEBUG("encoder %d CWB enabled, skipping\n",
> DRMID(phys->parent));
> --
> 2.39.5
>
--
With best wishes
Dmitry
