On 08/01/2023 23:56, Dmitry Baryshkov wrote:
On 06/12/2022 10:05, Jiasheng Jiang wrote:
As kzalloc may fail and return NULL pointer,
it should be better to check cstate
in order to avoid the NULL pointer dereference
in __drm_atomic_helper_crtc_reset.
Fixes: 1cff7440a86e ("drm/msm: Convert to using
__drm_atomic_helper_crtc_reset() for reset.")
Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index 13ce321283ff..22c2787b7b38 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -968,7 +968,10 @@ static void dpu_crtc_reset(struct drm_crtc *crtc)
if (crtc->state)
dpu_crtc_destroy_state(crtc, crtc->state);
- __drm_atomic_helper_crtc_reset(crtc, &cstate->base);
+ if (cstate)
+ __drm_atomic_helper_crtc_reset(crtc, &cstate->base);
+ else
+ __drm_atomic_helper_crtc_reset(crtc, NULL);
NAK.
The proper fix is to add the if() but to skip the else clause. We should
not reset the crtc's state if memory allocation failed.
On the other hand... Some of the drivers do exactly this ops.
With the message fixed:
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
--
With best wishes
Dmitry
