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From:   Cong Wang <xiyou.wangcong@gmail.com>
Date:   Mon, 10 Aug 2020 20:57:19 -0700
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Subject: Re: [Linux-kernel-mentees] [PATCH net] ipvs: Fix uninit-value in do_ip_vs_set_ctl()
To:     Peilin Ye <yepeilin.cs@gmail.com>
Cc:     Wensong Zhang <wensong@linux-vs.org>,
        Simon Horman <horms@verge.net.au>,
        Julian Anastasov <ja@ssi.bg>,
        Pablo Neira Ayuso <pablo@netfilter.org>,
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        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
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On Mon, Aug 10, 2020 at 3:10 PM Peilin Ye <yepeilin.cs@gmail.com> wrote:
>
> do_ip_vs_set_ctl() is referencing uninitialized stack value when `len` is
> zero. Fix it.

Which exact 'cmd' is it here?

I _guess_ it is one of those uninitialized in set_arglen[], which is 0.
But if that is the case, should it be initialized to
sizeof(struct ip_vs_service_user) instead because ip_vs_copy_usvc_compat()
is called anyway. Or, maybe we should just ban len==0 case.

In either case, it does not look like you fix it correctly.

Thanks.