netdev - Re: [PATCH net] tcp: switch snprintf to scnprintf

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Message-ID: <20191119015338.GD18865@dhcp-12-139.nay.redhat.com>
Date:   Tue, 19 Nov 2019 09:53:38 +0800
From:   Hangbin Liu <liuhangbin@...il.com>
To:     Eric Dumazet <eric.dumazet@...il.com>
Cc:     Jiri Benc <jbenc@...hat.com>, netdev@...r.kernel.org,
        Eric Dumazet <edumazet@...gle.com>,
        "David S . Miller" <davem@...emloft.net>
Subject: Re: [PATCH net] tcp: switch snprintf to scnprintf

On Fri, Nov 15, 2019 at 10:54:55AM +0100, Jiri Benc wrote:
> On Fri, 15 Nov 2019 10:41:06 +0800, Hangbin Liu wrote:
> > > We need to properly size the output buffers before using them,
> > > we can not afford truncating silently the output.
> > 
> > Yes, I agree. Just as I said, the buffer is still enough, while scnprintf
> > is just a safer usage compired with snprintf.
> 
> So maybe keep snprintf but add WARN_ON and bail out of the loop if the
> buffer size was reached?
> 
> 	if (WARN_ON(offs >= maxlen))
> 		break;
> 

Hi Eric,

What do you think?

Thanks
Hangbin