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Date:   Wed, 9 Aug 2023 01:38:55 +0200
From:   Florian Westphal <fw@strlen.de>
To:     Justin Stitt <justinstitt@google.com>
Cc:     Pablo Neira Ayuso <pablo@netfilter.org>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Florian Westphal <fw@strlen.de>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        linux-hardening@vger.kernel.org, Kees Cook <keescook@chromium.org>,
        netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/7] netfilter: ipset: refactor deprecated strncpy
Message-ID: <20230808233855.GI9741@breakpoint.cc>
References: <20230808-net-netfilter-v1-0-efbbe4ec60af@google.com>
 <20230808-net-netfilter-v1-1-efbbe4ec60af@google.com>
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Justin Stitt <justinstitt@google.com> wrote:
> Fixes several buffer overread bugs present in `ip_set_core.c` by using
> `strscpy` over `strncpy`.
> 
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>
> 
> ---
> There exists several potential buffer overread bugs here. These bugs
> exist due to the fact that the destination and source strings may have
> the same length which is equal to the max length `IPSET_MAXNAMELEN`.

There is no truncation.  Inputs are checked via nla_policy:

[IPSET_ATTR_SETNAME2]   = { .type = NLA_NUL_STRING, .len = IPSET_MAXNAMELEN - 1 },