From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, "Nikita V. Shirokov" <tehnerd@fb.com>,
        Alexei Starovoitov <ast@kernel.org>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.9 39/75] adding missing rcu_read_unlock in ipxip6_rcv
Date: Mon,  1 Jan 2018 15:32:16 +0100
Message-Id: <20180101140103.037344508@linuxfoundation.org>
In-Reply-To: <20180101140056.475827799@linuxfoundation.org>
References: <20180101140056.475827799@linuxfoundation.org>
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Sender: linux-kernel-owner@vger.kernel.org

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: "Nikita V. Shirokov" <tehnerd@fb.com>


[ Upstream commit 74c4b656c3d92ec4c824ea1a4afd726b7b6568c8 ]

commit 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
introduced new exit point in  ipxip6_rcv. however rcu_read_unlock is
missing there. this diff is fixing this

v1->v2:
 instead of doing rcu_read_unlock in place, we are going to "drop"
 section (to prevent skb leakage)

Fixes: 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
Signed-off-by: Nikita V. Shirokov <tehnerd@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv6/ip6_tunnel.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -911,7 +911,7 @@ static int ipxip6_rcv(struct sk_buff *sk
 		if (t->parms.collect_md) {
 			tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
 			if (!tun_dst)
-				return 0;
+				goto drop;
 		}
 		ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 				    log_ecn_error);