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From:   Kenny Ho <y2kenny@gmail.com>
Date:   Wed, 24 May 2023 14:01:17 -0400
Message-ID: <CAOWid-dYtkcKuNxoOyf3yqSJ7OtcNjaqJLVX1QhRUhYSOO6vHA@mail.gmail.com>
Subject: Re: [PATCH] Remove hardcoded static string length
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Marc Dionne <marc.dionne@auristor.com>,
        Kenny Ho <Kenny.Ho@amd.com>,
        David Howells <dhowells@redhat.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-afs@lists.infradead.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
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On Wed, May 24, 2023 at 1:43=E2=80=AFPM Andrew Lunn <andrew@lunn.ch> wrote:
>
> The other end of the socket should not blow up, because that would be
> an obvious DOS or buffer overwrite attack vector. So you need to
> decide, do you want to expose such issues and see if anything does
> actually blow up, or do you want to do a bit more work and correctly
> terminate the string when capped?

Right... I guess it's not clear to me that existing implementations
null-terminate correctly when UTS_RELEASE causes the string to exceed
the 65 byte size of rxrpc_version_string.  We can of course do better,
but I hesitate to do strncpy because I am not familiar with this code
base enough to tell if this function is part of some hot path where
strncpy matters.

Regards,
Kenny