This is a note to let you know that I've just added the patch titled ipv6: sctp: add rcu protection around np->opt to the 3.18-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-sctp-add-rcu-protection-around-np-opt.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c836a8ba93869d6a0290a6ae0047fbef09066871 Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Wed, 2 Dec 2015 21:48:14 -0800 Subject: ipv6: sctp: add rcu protection around np->opt From: Eric Dumazet <edumazet@xxxxxxxxxx> commit c836a8ba93869d6a0290a6ae0047fbef09066871 upstream. This patch completes the work I did in commit 45f6fad84cc3 ("ipv6: add complete rcu protection around np->opt"), as I missed sctp part. This simply makes sure np->opt is used with proper RCU locking and accessors. Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sctp/ipv6.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -209,6 +209,7 @@ static int sctp_v6_xmit(struct sk_buff * struct sock *sk = skb->sk; struct ipv6_pinfo *np = inet6_sk(sk); struct flowi6 *fl6 = &transport->fl.u.ip6; + int res; pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb, skb->len, &fl6->saddr, &fl6->daddr); @@ -220,7 +221,10 @@ static int sctp_v6_xmit(struct sk_buff * SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS); - return ip6_xmit(sk, skb, fl6, np->opt, np->tclass); + rcu_read_lock(); + res = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt), np->tclass); + rcu_read_unlock(); + return res; } /* Returns the dst cache entry for the given source and destination ip @@ -262,7 +266,10 @@ static void sctp_v6_get_dst(struct sctp_ pr_debug("src=%pI6 - ", &fl6->saddr); } - final_p = fl6_update_dst(fl6, np->opt, &final); + rcu_read_lock(); + final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); + rcu_read_unlock(); + dst = ip6_dst_lookup_flow(sk, fl6, final_p); if (!asoc || saddr) goto out; @@ -321,7 +328,7 @@ static void sctp_v6_get_dst(struct sctp_ if (baddr) { fl6->saddr = baddr->v6.sin6_addr; fl6->fl6_sport = baddr->v6.sin6_port; - final_p = fl6_update_dst(fl6, np->opt, &final); + final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); dst = ip6_dst_lookup_flow(sk, fl6, final_p); } Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are queue-3.18/ipv6-sctp-add-rcu-protection-around-np-opt.patch queue-3.18/ipv6-sctp-fix-lockdep-splat-in-sctp_v6_get_dst.patch