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: Maxim Korotkov <korotkov.maxim.s@gmail.com>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20221122122901.22294-1-korotkov.maxim.s@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Maxim Korotkov 2022-11-22 15:29:01 +03:00 committed by Jakub Kicinski
parent 2094dbbd82
commit 64a8f8f712

View File

@ -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();