Messages in this thread | | | From | Alexander Lobakin <> | Subject | Re: [PATCH v3] ethtool: avoiding integer overflow in ethtool_phys_id() | Date | Tue, 22 Nov 2022 14:39:08 +0100 |
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From: Maxim Korotkov <korotkov.maxim.s@gmail.com> Date: Tue, 22 Nov 2022 15:29:01 +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>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.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..6b59e7a1c906 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); > + u64 i = 0; > > do { > rtnl_lock(); > -- > 2.17.1
Some notes to the process, not the code:
1) I asked to add my Reviewed-by to v3 in the previous thread, it's mandatory for authors to pick-up all the tags before publishing a new revision; 2) when sending v2, v3, ... vN, please have a changelog in the commit message or right below those '---' after your SoB, that makes it easier to review.
Thanks, Olek
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