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From:   Jason Xing <kerneljasonxing@gmail.com>
Date:   Sat, 7 May 2022 09:26:07 +0800
Message-ID: <CAL+tcoBwQ2tijfzwOO6zb2MobCL27PcyN3foRcAw91MpyWg_VA@mail.gmail.com>
Subject: Re: [PATCH net-next] net: use the %px format to display sock
To:     Peilin Ye <yepeilin.cs@gmail.com>
Cc:     davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org,
        kuba@kernel.org, pabeni@redhat.com, ast@kernel.org,
        daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com,
        songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com,
        kpsingh@kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
        Jason Xing <xingwanli@kuaishou.com>
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On Sat, May 7, 2022 at 2:56 AM Peilin Ye <yepeilin.cs@gmail.com> wrote:
>
> Hi Jason,
>
> On Thu, May 05, 2022 at 09:08:26PM +0800, kerneljasonxing@gmail.com wrote:
> > -             pr_err("Attempt to release TCP socket in state %d %p\n",
> > +             pr_err("Attempt to release TCP socket in state %d %px\n",
>
> I think we cannot use %px here for security reasons?  checkpatch is also
> warning about it:
>

I noticed this warning before submitting. Since the %p format doesn't
print the real address, printing the address here will be helpless and
we cannot trace what exactly the bad socket is.

What do you suggest?

Thanks,
Jason

> WARNING: Using vsprintf specifier '%px' potentially exposes the kernel memory layout, if you don't really need the address please consider using '%p'.
> #21: FILE: net/ipv4/af_inet.c:142:
> +               pr_err("Attempt to release TCP socket in state %d %px\n",
>                        sk->sk_state, sk);
>
> Thanks,
> Peilin Ye
>