Commit d761b945 authored by Jason-JH.Lin's avatar Jason-JH.Lin Committed by Chun-Kuang Hu
Browse files

drm/mediatek: Add cnt checking for coverity issue 



CERT-C Characters and Strings (CERT STR31-C)
all_drm_priv[cnt] evaluates to an address that could be at negative
offset of an array.

In mtk_drm_get_all_drm_priv():
Guarantee that storage for strings has sufficient space for character
data and the null terminator.

So change cnt to unsigned int and check its max value.

Fixes: 1ef7ed48 ("drm/mediatek: Modify mediatek-drm for mt8195 multi mmsys support")
Signed-off-by: default avatarJason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: default avatarCK Hu <ck.hu@mediatek.com>
Reviewed-by: default avatarAlexandre Mergnat <amergnat@baylibre.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230714094908.13087-3-jason-jh.lin@mediatek.com/


Signed-off-by: default avatarChun-Kuang Hu <chunkuang.hu@kernel.org>
parent 27b9e2ea

drivers/gpu/drm/mediatek/mtk_drm_drv.c

+4 −1
Original line number Diff line number Diff line
@@ -354,7 +354,7 @@ static bool mtk_drm_get_all_drm_priv(struct device *dev) 
	const struct of_device_id *of_id;

	struct device_node *node;

	struct device *drm_dev;

	int cnt = 0;

	unsigned int cnt = 0;

	int i, j;



	for_each_child_of_node(phandle->parent, node) {
@@ -375,6 +375,9 @@ static bool mtk_drm_get_all_drm_priv(struct device *dev) 
		all_drm_priv[cnt] = dev_get_drvdata(drm_dev);

		if (all_drm_priv[cnt] && all_drm_priv[cnt]->mtk_drm_bound)

			cnt++;



		if (cnt == MAX_CRTC)

			break;

	}



	if (drm_priv->data->mmsys_dev_num == cnt) {