Commit 79a1f0cc authored Jun 01, 2020 by Hangbin Liu Committed by David S. Miller Jun 01, 2020

ipv6: fix IPV6_ADDRFORM operation logic



Socket option IPV6_ADDRFORM supports UDP/UDPLITE and TCP at present.
Previously the checking logic looks like:
if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE)
	do_some_check;
else if (sk->sk_protocol != IPPROTO_TCP)
	break;

After commit b6f61189 ("ipv6: restrict IPV6_ADDRFORM operation"), TCP
was blocked as the logic changed to:
if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE)
	do_some_check;
else if (sk->sk_protocol == IPPROTO_TCP)
	do_some_check;
	break;
else
	break;

Then after commit 82c9ae44 ("ipv6: fix restrict IPV6_ADDRFORM operation")
UDP/UDPLITE were blocked as the logic changed to:
if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE)
	do_some_check;
if (sk->sk_protocol == IPPROTO_TCP)
	do_some_check;

if (sk->sk_protocol != IPPROTO_TCP)
	break;

Fix it by using Eric's code and simply remove the break in TCP check, which
looks like:
if (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_UDPLITE)
	do_some_check;
else if (sk->sk_protocol == IPPROTO_TCP)
	do_some_check;
else
	break;

Fixes: 82c9ae44 ("ipv6: fix restrict IPV6_ADDRFORM operation")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 4c21daae

net/ipv6/ipv6_sockglue.c

+7 −6

Original line number	Diff line number	Diff line
		@@ -218,14 +218,15 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
		retv = -EBUSY;
		break;
		}
		}
		if (sk->sk_protocol == IPPROTO_TCP &&
		sk->sk_prot != &tcpv6_prot) {
		} else if (sk->sk_protocol == IPPROTO_TCP) {
		if (sk->sk_prot != &tcpv6_prot) {
		retv = -EBUSY;
		break;
		}
		if (sk->sk_protocol != IPPROTO_TCP)
		} else {
		break;
		}

		if (sk->sk_state != TCP_ESTABLISHED) {
		retv = -ENOTCONN;
		break;

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