UPSTREAM: sctp: do not inherit ipv6_{mc|ac|fl}_list from parent

SCTP needs fixes similar to 83eaddab4378 ("ipv6/dccp: do not inherit
ipv6_mc_list from parent"), otherwise bad things can happen.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit fdcee2cbb8438702ea1b328fb6e0ac5e9a40c7f8)
Signed-off-by: Connor O'Brien <connoro@google.com>
Bug: 62298712
Change-Id: I386efa7b8e8a99b22830a9593c92a41232ab03bb

net/sctp/ipv6.c

@@ -657,6 +657,9 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 	newnp = inet6_sk(newsk);
 
 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
+	newnp->ipv6_mc_list = NULL;
+	newnp->ipv6_ac_list = NULL;
+	newnp->ipv6_fl_list = NULL;
 
 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 	 * and getpeername().