| Message ID | 20250309095525.7738-1-qasdev00@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] drm/msm/dpu: reorder pointer operations after sanity checks to avoid NULL deref | expand |
On Sun, Mar 09, 2025 at 09:55:25AM +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. > > Fixes: 8144d17a81d9 ("drm/msm/dpu: Skip trigger flush and start for CWB") > Signed-off-by: Qasim Ijaz <qasdev00@gmail.com> > --- > v2: > - Moved Signed-off tag below Fixes tag > - Moved dpu_enc declaration to the top and initialisation below sanity checks > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c index 0eed93a4d056..0bd1f2bfaaff 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -1667,7 +1667,7 @@ 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); + struct dpu_encoder_virt *dpu_enc; if (!phys) { DPU_ERROR("invalid argument(s)\n"); @@ -1678,6 +1678,8 @@ static void _dpu_encoder_trigger_start(struct dpu_encoder_phys *phys) DPU_ERROR("invalid pingpong hw\n"); return; } + + dpu_enc = to_dpu_encoder_virt(phys->parent); if (phys->parent->encoder_type == DRM_MODE_ENCODER_VIRTUAL && dpu_enc->cwb_mask) {
_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. Fixes: 8144d17a81d9 ("drm/msm/dpu: Skip trigger flush and start for CWB") Signed-off-by: Qasim Ijaz <qasdev00@gmail.com> --- v2: - Moved Signed-off tag below Fixes tag - Moved dpu_enc declaration to the top and initialisation below sanity checks drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)