From 2a34496fef841e8d89a4ccd1a48c7fd664b5c84f Mon Sep 17 00:00:00 2001 From: Qasim Ijaz Date: Tue, 8 Apr 2025 18:22:23 +0100 Subject: [PATCH] drm/msm/dpu: reorder pointer operations after sanity checks to avoid NULL deref _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") Reviewed-by: Dmitry Baryshkov Signed-off-by: Qasim Ijaz Reviewed-by: Jessica Zhang Reviewed-by: Abhinav Kumar Patchwork: https://patchwork.freedesktop.org/patch/647536/ Link: https://lore.kernel.org/r/20250408172223.10827-1-qasdev00@gmail.com Signed-off-by: Abhinav Kumar --- drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c index 284e69bb47c1..dd13dc4e95a4 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -1666,7 +1666,7 @@ 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) return; } + dpu_enc = to_dpu_encoder_virt(phys->parent); + if (phys->parent->encoder_type == DRM_MODE_ENCODER_VIRTUAL && dpu_enc->cwb_mask) { DPU_DEBUG("encoder %d CWB enabled, skipping\n", DRMID(phys->parent));