This is a note to let you know that I've just added the patch titled ipv6: Fix datagram socket connection with DSCP. to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv6-fix-datagram-socket-connection-with-dscp.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e010ae08c71fda8be3d6bda256837795a0b3ea41 Mon Sep 17 00:00:00 2001 From: Guillaume Nault <gnault@xxxxxxxxxx> Date: Wed, 8 Feb 2023 18:13:59 +0100 Subject: ipv6: Fix datagram socket connection with DSCP. From: Guillaume Nault <gnault@xxxxxxxxxx> commit e010ae08c71fda8be3d6bda256837795a0b3ea41 upstream. Take into account the IPV6_TCLASS socket option (DSCP) in ip6_datagram_flow_key_init(). Otherwise fib6_rule_match() can't properly match the DSCP value, resulting in invalid route lookup. For example: ip route add unreachable table main 2001:db8::10/124 ip route add table 100 2001:db8::10/124 dev eth0 ip -6 rule add dsfield 0x04 table 100 echo test | socat - UDP6:[2001:db8::11]:54321,ipv6-tclass=0x04 Without this patch, socat fails at connect() time ("No route to host") because the fib-rule doesn't jump to table 100 and the lookup ends up being done in the main table. Fixes: 2cc67cc731d9 ("[IPV6] ROUTE: Routing by Traffic Class.") Signed-off-by: Guillaume Nault <gnault@xxxxxxxxxx> Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reviewed-by: David Ahern <dsahern@xxxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv6/datagram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv6/datagram.c +++ b/net/ipv6/datagram.c @@ -51,7 +51,7 @@ static void ip6_datagram_flow_key_init(s fl6->flowi6_mark = sk->sk_mark; fl6->fl6_dport = inet->inet_dport; fl6->fl6_sport = inet->inet_sport; - fl6->flowlabel = np->flow_label; + fl6->flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label); fl6->flowi6_uid = sk->sk_uid; if (!oif) Patches currently in stable-queue which might be from gnault@xxxxxxxxxx are queue-6.1/ipv6-fix-datagram-socket-connection-with-dscp.patch queue-6.1/ipv6-fix-tcp-socket-connection-with-dscp.patch