Messages in this thread | | | From | Alexander Lobakin <> | Subject | Re: [PATCH v2] ethtool: avoiding integer overflow in ethtool_phys_id() | Date | Tue, 22 Nov 2022 13:14:00 +0100 |
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From: Maxim Korotkov <korotkov.maxim.s@gmail.com> Date: Tue, 22 Nov 2022 09:54:23 +0300
> 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> > --- > 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 6a7308de192d..f845e8be4d7c 100644 > --- a/net/ethtool/ioctl.c > +++ b/net/ethtool/ioctl.c > @@ -2007,7 +2007,8 @@ 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);
^^
Meh, you forgot to put a space after the comma :s
Other than that (please add it to a v3):
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
> + u64 i = 0; > > do { > rtnl_lock(); > -- > 2.17.1
Thanks, Olek
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