On Fri May 31, 2024 at 3:56 PM CEST, Huai-Yuan Liu wrote:
> In malidp_tegra_crtc_reset, new memory is allocated with kzalloc, but
> no check is performed. Before calling __drm_atomic_helper_crtc_reset,
> mw_state should be checked to prevent possible null pointer dereferene.
Please check that all these variable name references actually are valid.
Also, "dereference".
> Fixes: b7e0b04ae450 ("drm/tegra: Convert to using __drm_atomic_helper_crtc_reset() for reset.")
> Signed-off-by: Huai-Yuan Liu <qq810974084@xxxxxxxxx>
> ---
> drivers/gpu/drm/tegra/dc.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
> index be61c9d1a4f0..7648e129c212 100644
> --- a/drivers/gpu/drm/tegra/dc.c
> +++ b/drivers/gpu/drm/tegra/dc.c
> @@ -1388,7 +1388,8 @@ static void tegra_crtc_reset(struct drm_crtc *crtc)
> if (crtc->state)
> tegra_crtc_atomic_destroy_state(crtc, crtc->state);
>
> - __drm_atomic_helper_crtc_reset(crtc, &state->base);
> + if (state)
> + __drm_atomic_helper_crtc_reset(crtc, &state->base);
Looking at how other drivers do this, they call
__drm_atomic_helper_crtc_reset(crtc, NULL);
if they fail to allocate a new state. Any reason why we wouldn't want to
do the same thing here?
Thierry
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