Re: [PATCH 9/9] udpv6: Check address length before reading address family

From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Andrey Ignatov <rdna@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>, Martin Lau <kafai@fb.com>,
	Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
	"David S. Miller" <davem@davemloft.net>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH 9/9] udpv6: Check address length before reading address family
Date: Sat, 13 Apr 2019 11:06:25 +0900	[thread overview]
Message-ID: <639b9e9a-dc4e-9e6d-7437-b66d6acd3a16@i-love.sakura.ne.jp> (raw)
In-Reply-To: <20190412164927.GA28199@rdna-mbp>

On 2019/04/13 1:49, Andrey Ignatov wrote:
> Such a check wasn't added since it's already checked in
> inet_dgram_connect, the only place where udpv6_pre_connect is called:
> 
>   int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
>                          int addr_len, int flags)
>   {
>           struct sock *sk = sock->sk;
>           int err;
>   
>           if (addr_len < sizeof(uaddr->sa_family))
>                   return -EINVAL;
>           if (uaddr->sa_family == AF_UNSPEC)
>                   return sk->sk_prot->disconnect(sk, flags);
>   
>           if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
>                   err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
>                   if (err)
>                           return err;
>           }
> 
> So it's already handled. But if it helps KMSAN, that's probably fine to
> double-check it here. Or it's considered false positive?

OK, then KMSAN will not complain and this patch can be dropped.