From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
        David Ahern <dsahern@kernel.org>,
        Willem de Bruijn <willemb@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>, Xintong Hu <huxintong@fb.com>
Subject: [PATCH 5.4 253/355] udp6: allow SO_MARK ctrl msg to affect routing
Date:   Mon, 15 Nov 2021 18:02:57 +0100
Message-Id: <20211115165321.928988019@linuxfoundation.org>
In-Reply-To: <20211115165313.549179499@linuxfoundation.org>
References: <20211115165313.549179499@linuxfoundation.org>
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From: Jakub Kicinski <kuba@kernel.org>

[ Upstream commit 42dcfd850e514b229d616a53dec06d0f2533217c ]

Commit c6af0c227a22 ("ip: support SO_MARK cmsg")
added propagation of SO_MARK from cmsg to skb->mark.
For IPv4 and raw sockets the mark also affects route
lookup, but in case of IPv6 the flow info is
initialized before cmsg is parsed.

Fixes: c6af0c227a22 ("ip: support SO_MARK cmsg")
Reported-and-tested-by: Xintong Hu <huxintong@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/ipv6/udp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 0f57c682afdd8..818fc99756256 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1363,7 +1363,6 @@ do_udp_sendmsg:
 	if (!fl6.flowi6_oif)
 		fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
 
-	fl6.flowi6_mark = ipc6.sockc.mark;
 	fl6.flowi6_uid = sk->sk_uid;
 
 	if (msg->msg_controllen) {
@@ -1399,6 +1398,7 @@ do_udp_sendmsg:
 	ipc6.opt = opt;
 
 	fl6.flowi6_proto = sk->sk_protocol;
+	fl6.flowi6_mark = ipc6.sockc.mark;
 	fl6.daddr = *daddr;
 	if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
 		fl6.saddr = np->saddr;
-- 
2.33.0