[PATCH net-next] net: phy: mdio-bcm-unimac: Cast denominator to unsigned long to avoid overflow

From: Daniil Dulov
Date: Tue Mar 12 2024 - 12:55:12 EST


The expression priv->clk_freq * 2 can lead to overflow that will cause
a division by zero. So, let's cast it to unsigned long to avoid it.

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

Signed-off-by: Daniil Dulov <d.dulov@xxxxxxxxxx>
---
drivers/net/mdio/mdio-bcm-unimac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/mdio/mdio-bcm-unimac.c b/drivers/net/mdio/mdio-bcm-unimac.c
index f40eb50bb978..0425b622c09f 100644
--- a/drivers/net/mdio/mdio-bcm-unimac.c
+++ b/drivers/net/mdio/mdio-bcm-unimac.c
@@ -214,7 +214,7 @@ static int unimac_mdio_clk_set(struct unimac_mdio_priv *priv)
else
rate = clk_get_rate(priv->clk);

- div = (rate / (2 * priv->clk_freq)) - 1;
+ div = (rate / (2 * (unsigned long)priv->clk_freq)) - 1;
if (div & ~MDIO_CLK_DIV_MASK) {
pr_warn("Incorrect MDIO clock frequency, ignoring\n");
ret = 0;
--
2.25.1