From 82c9ae440857840c56e05d4fb1427ee032531346 Mon Sep 17 00:00:00 2001
From: John Haxby <john.haxby@oracle.com>
Date: Sat, 18 Apr 2020 16:30:49 +0100
Subject: [PATCH] ipv6: fix restrict IPV6_ADDRFORM operation
Commit b6f6118901d1 ("ipv6: restrict IPV6_ADDRFORM operation") fixed a
problem found by syzbot an unfortunate logic error meant that it
also broke IPV6_ADDRFORM.
Rearrange the checks so that the earlier test is just one of the series
of checks made before moving the socket from IPv6 to IPv4.
Fixes: b6f6118901d1 ("ipv6: restrict IPV6_ADDRFORM operation")
Signed-off-by: John Haxby <john.haxby@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv6/ipv6_sockglue.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index debdaeba5d8c1..18d05403d3b52 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -183,15 +183,14 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
retv = -EBUSY;
break;
}
- } else if (sk->sk_protocol == IPPROTO_TCP) {
- if (sk->sk_prot != &tcpv6_prot) {
- retv = -EBUSY;
- break;
- }
- break;
- } else {
+ }
+ if (sk->sk_protocol == IPPROTO_TCP &&
+ sk->sk_prot != &tcpv6_prot) {
+ retv = -EBUSY;
break;
}
+ if (sk->sk_protocol != IPPROTO_TCP)
+ break;
if (sk->sk_state != TCP_ESTABLISHED) {
retv = -ENOTCONN;
break;