* [PATCH v1 1/1] drm/mediatek: Fix wrong check of nvmem_cell_read
@ 2024-09-25 8:40 Liankun Yang
2024-09-26 9:33 ` AngeloGioacchino Del Regno
0 siblings, 1 reply; 2+ messages in thread
From: Liankun Yang @ 2024-09-25 8:40 UTC (permalink / raw)
To: chunkuang.hu, p.zabel, airlied, simona, matthias.bgg,
angelogioacchino.delregno, rex-bc.chen, msp, granquet,
dmitry.osipenko, jitao.shi, mac.shen, peng.liu, liankun.yang
Cc: Project_Global_Chrome_Upstream_Group, dri-devel, linux-mediatek,
linux-kernel, linux-arm-kernel
If the len is 0, kernel crash will occur when performing operations.
Add the len check conditions to prevent kernel crash.
Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: Liankun Yang <liankun.yang@mediatek.com>
---
drivers/gpu/drm/mediatek/mtk_dp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index d8796a904eca..0cc75ba96b98 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -1082,7 +1082,7 @@ static void mtk_dp_get_calibration_data(struct mtk_dp *mtk_dp)
buf = (u32 *)nvmem_cell_read(cell, &len);
nvmem_cell_put(cell);
- if (IS_ERR(buf) || ((len / sizeof(u32)) != 4)) {
+ if (IS_ERR(buf) || (len == 0) || ((len / sizeof(u32)) != 4)) {
dev_warn(dev, "Failed to read nvmem_cell_read\n");
if (!IS_ERR(buf))
--
2.45.2
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH v1 1/1] drm/mediatek: Fix wrong check of nvmem_cell_read
2024-09-25 8:40 [PATCH v1 1/1] drm/mediatek: Fix wrong check of nvmem_cell_read Liankun Yang
@ 2024-09-26 9:33 ` AngeloGioacchino Del Regno
0 siblings, 0 replies; 2+ messages in thread
From: AngeloGioacchino Del Regno @ 2024-09-26 9:33 UTC (permalink / raw)
To: Liankun Yang, chunkuang.hu, p.zabel, airlied, simona,
matthias.bgg, rex-bc.chen, msp, granquet, dmitry.osipenko,
jitao.shi, mac.shen, peng.liu
Cc: Project_Global_Chrome_Upstream_Group, dri-devel, linux-mediatek,
linux-kernel, linux-arm-kernel
Il 25/09/24 10:40, Liankun Yang ha scritto:
> If the len is 0, kernel crash will occur when performing operations.
> Add the len check conditions to prevent kernel crash.
>
Please fix the commit title:
drm/mediatek: mtk_dp: Fix potential KP on 0 bytes nvmem cell read
> Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
>
Please remove this blank line between the Fixes tag and your S-o-b.
> Signed-off-by: Liankun Yang <liankun.yang@mediatek.com>
> ---
> drivers/gpu/drm/mediatek/mtk_dp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
> index d8796a904eca..0cc75ba96b98 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dp.c
> @@ -1082,7 +1082,7 @@ static void mtk_dp_get_calibration_data(struct mtk_dp *mtk_dp)
> buf = (u32 *)nvmem_cell_read(cell, &len);
> nvmem_cell_put(cell);
>
> - if (IS_ERR(buf) || ((len / sizeof(u32)) != 4)) {
> + if (IS_ERR(buf) || (len == 0) || ((len / sizeof(u32)) != 4)) {
if (IS_ERR(buf) || !len || ((len / sizeof(u32)) != 4)) {
Cheers,
Angelo
^ permalink raw reply [flat|nested] 2+ messages in thread
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2024-09-25 8:40 [PATCH v1 1/1] drm/mediatek: Fix wrong check of nvmem_cell_read Liankun Yang
2024-09-26 9:33 ` AngeloGioacchino Del Regno
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