Commit 64a8f8f7 authored by Maxim Korotkov's avatar Maxim Korotkov Committed by Jakub Kicinski
Browse files

ethtool: avoiding integer overflow in ethtool_phys_id() 



The value of an arithmetic expression "n * id.data" is subject
to possible overflow due to a failure to cast operands to a larger data
type before performing arithmetic. Used macro for multiplication instead
operator for avoiding overflow.

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

Signed-off-by: default avatarMaxim Korotkov <korotkov.maxim.s@gmail.com>
Reviewed-by: default avatarAlexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20221122122901.22294-1-korotkov.maxim.s@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 2094dbbd

net/ethtool/ioctl.c

+2 −1
Original line number Diff line number Diff line
@@ -2013,7 +2013,8 @@ static int ethtool_phys_id(struct net_device *dev, void __user *useraddr) 
	} else {

		/* Driver expects to be called at twice the frequency in rc */

		int n = rc * 2, interval = HZ / n;

		u64 count = n * id.data, i = 0;

		u64 count = mul_u32_u32(n, id.data);

		u64 i = 0;



		do {

			rtnl_lock();