From: Jakub Kicinski <kuba@kernel.org>
To: Kees Cook <keescook@chromium.org>
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>,
Paolo Abeni <pabeni@redhat.com>,
syzbot <syzkaller@googlegroups.com>,
netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
netdev@vger.kernel.org,
Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH v3] netlink: Bounds-check struct nlmsgerr creation
Date: Thu, 1 Sep 2022 14:34:23 -0700 [thread overview]
Message-ID: <20220901143423.2abc0ab0@kernel.org> (raw)
In-Reply-To: <20220901071336.1418572-1-keescook@chromium.org>
On Thu, 1 Sep 2022 00:13:36 -0700 Kees Cook wrote:
> rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
> NLMSG_ERROR, payload, flags);
All we should need here is __nlmsg_put() -> nlmsg_put(),
that's idiomatic for netlink.
> errmsg = nlmsg_data(rep);
> errmsg->error = err;
> - memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
> + unsafe_memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg)
> + ? nlh->nlmsg_len : sizeof(*nlh),
> + /* "payload" was bounds checked against nlh->nlmsg_len,
> + * and overflow-checked as tlvlen was constructed.
> + */);
next prev parent reply other threads:[~2022-09-01 21:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 7:13 [PATCH v3] netlink: Bounds-check struct nlmsgerr creation Kees Cook
2022-09-01 21:34 ` Jakub Kicinski [this message]
2022-09-02 23:08 ` Kees Cook
2022-09-03 2:53 ` Jakub Kicinski
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