From: Maxim Korotkov korotkov.maxim.s@gmail.com
[ Upstream commit 64a8f8f7127da228d59a39e2c5e75f86590f90b4 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- net/ethtool/ioctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index e4983f473a3c..6991d77dcb2e 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -1988,7 +1988,8 @@ 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();