2023-04-05 20:28:02

by Nur Hussein

Subject: [PATCH] drm/tegra : Avoid potential integer overflow of 32 bit int

In tegra_sor_compute_config(), the 32-bit value mode->clock
is multiplied by 1000, and assigned to the u64 variable pclk.
We can avoid a potential 32-bit integer overflow by casting
mode->clock to u64 before we do the arithmetic and assignment.

Signed-off-by: Nur Hussein <[email protected]>
---
drivers/gpu/drm/tegra/sor.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tegra/sor.c b/drivers/gpu/drm/tegra/sor.c
index cd25f409979c..8d910695775c 100644
--- a/drivers/gpu/drm/tegra/sor.c
+++ b/drivers/gpu/drm/tegra/sor.c
@@ -1153,7 +1153,7 @@ static int tegra_sor_compute_config(struct tegra_sor *sor,
struct drm_dp_link *link)
{
const u64 f = 100000, link_rate = link->rate * 1000;
- const u64 pclk = mode->clock * 1000;
+ const u64 pclk = (u64)mode->clock * 1000;
u64 input, output, watermark, num;
struct tegra_sor_params params;
u32 num_syms_per_line;
--
2.34.1

2023-04-06 12:06:36

by Thierry Reding

Subject: Re: [PATCH] drm/tegra : Avoid potential integer overflow of 32 bit int

From: Thierry Reding <[email protected]>

On Thu, 6 Apr 2023 04:25:59 +0800, Nur Hussein wrote:
> In tegra_sor_compute_config(), the 32-bit value mode->clock
> is multiplied by 1000, and assigned to the u64 variable pclk.
> We can avoid a potential 32-bit integer overflow by casting
> mode->clock to u64 before we do the arithmetic and assignment.
>
>

Applied, thanks!

[1/1] drm/tegra : Avoid potential integer overflow of 32 bit int
(no commit info)

Best regards,
--
Thierry Reding <[email protected]>