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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Tue, 21 Dec 2021 10:23:38 +0100
Message-ID: <CAK8P3a3zQm7zJWprcYq47VZD0ZZsuOTR3w7a8k78VH=3he2Fdw@mail.gmail.com>
Subject: Re: [PATCH] net: dl2k: replace strlcpy with strscpy
To:     Jason Wang <wangborong@cdjrlc.com>
Cc:     Jakub Kicinski <kuba@kernel.org>,
        David Miller <davem@davemloft.net>,
        Arnd Bergmann <arnd@arndb.de>, Jason Gunthorpe <jgg@ziepe.ca>,
        Networking <netdev@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Tue, Dec 21, 2021 at 8:14 AM Jason Wang <wangborong@cdjrlc.com> wrote:
>
> The strlcpy should not be used because it doesn't limit the source
> length. So that it will lead some potential bugs.
>
> But the strscpy doesn't require reading memory from the src string
> beyond the specified "count" bytes, and since the return value is
> easier to error-check than strlcpy()'s. In addition, the implementation
> is robust to the string changing out from underneath it, unlike the
> current strlcpy() implementation.
>
> Thus, replace strlcpy with strscpy.
>
> Signed-off-by: Jason Wang <wangborong@cdjrlc.com>

Are you trying to eliminate strlcpy() from all 800 files using it
completely? If not, I don't see a need to fix individual drivers
that use a constant source string and don't use the return
code, as the behavior should be the same.

While it seems reasonable to converge towards a more robust
string copy, none of the points you list in the changelog apply to
the function you patch here.

        Arnd