drm/nouveau/clk: prevent division by zero in gt215_clk_info()

[PATCH] drm/nouveau/clk: prevent division by zero in gt215_clk_info()

Igor Artemiev posted 1 patch 1 month, 4 weeks ago

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drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c | 3 +++
1 file changed, 3 insertions(+)

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[PATCH] drm/nouveau/clk: prevent division by zero in gt215_clk_info()

Posted by Igor Artemiev 1 month, 4 weeks ago

sdiv can be zero if read_vco() returns 0 or khz is greater than sclk*2.
This value will cause a division-by-zero error in the gt215_clk_info() function.

Add a check before division. 

Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.

Signed-off-by: Igor Artemiev <Igor.A.Artemiev@mcst.ru>
---
 drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c
index b5f3969727a2..4c53442b4167 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c
@@ -206,6 +206,9 @@ gt215_clk_info(struct nvkm_clk *base, int idx, u32 khz,
 	default:
 		sclk = read_vco(clk, idx);
 		sdiv = min((sclk * 2) / khz, (u32)65);
+		if (!sdiv)
+			return -EINVAL;
+
 		oclk = (sclk * 2) / sdiv;
 		diff = ((khz + 3000) - oclk);
 
-- 
2.39.2