[PATCH AUTOSEL 6.1 21/33] drm/tegra: Avoid potential 32-bit integer overflow

Sasha Levin
2023-05-01T03:12:50Z

From: Nur Hussein <hussein@unixcat.org>

[ Upstream commit 2429b3c529da29d4277d519bd66d034842dcd70c ]

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 <hussein@unixcat.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 8af632740673a..77723d5f1d3fd 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;
--
2.39.2