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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240312165358.7712-1-d.dulov@aladdin.ru>
Date: Tue, 12 Mar 2024 19:53:58 +0300
From: Daniil Dulov <d.dulov@...ddin.ru>
To: Jakub Kicinski <kuba@...nel.org>, Florian Fainelli
	<florian.fainelli@...adcom.com>
CC: Daniil Dulov <d.dulov@...ddin.ru>, Broadcom internal kernel review list
	<bcm-kernel-feedback-list@...adcom.com>, Andrew Lunn <andrew@...n.ch>, Heiner
 Kallweit <hkallweit1@...il.com>, Russell King <linux@...linux.org.uk>, "David
 S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Doug
 Berger <opendmb@...il.com>, Paolo Abeni <pabeni@...hat.com>,
	<netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<lvc-project@...uxtesting.org>
Subject: [PATCH net-next] net: phy: mdio-bcm-unimac: Cast denominator to unsigned long to avoid overflow

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@...ddin.ru>
---
 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