This is a note to let you know that I've just added the patch titled

sctp: full support for ipv6 ip_nonlocal_bind & IP_FREEBIND

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: sctp-full-support-for-ipv6-ip_nonlocal_bind-ip_freebind.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Wed Nov 15 17:24:03 CET 2017

From: Laszlo Toth laszlth@gmail.com Date: Mon, 23 Oct 2017 19:19:33 +0200 Subject: sctp: full support for ipv6 ip_nonlocal_bind & IP_FREEBIND

From: Laszlo Toth laszlth@gmail.com

[ Upstream commit b71d21c274eff20a9db8158882b545b141b73ab8 ]

Commit 9b9742022888 ("sctp: support ipv6 nonlocal bind") introduced support for the above options as v4 sctp did, so patched sctp_v6_available().

In the v4 implementation it's enough, because sctp_inet_bind_verify() just returns with sctp_v4_available(). However sctp_inet6_bind_verify() has an extra check before that for link-local scope_id, which won't respect the above options.

Added the checks before calling ipv6_chk_addr(), but not before the validation of scope_id.

before (w/ both options): ./v6test fe80::10 sctp bind failed, errno: 99 (Cannot assign requested address) ./v6test fe80::10 tcp bind success, errno: 0 (Success)

after (w/ both options): ./v6test fe80::10 sctp bind success, errno: 0 (Success)

Signed-off-by: Laszlo Toth laszlth@gmail.com Reviewed-by: Xin Long lucien.xin@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sctp/ipv6.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -881,8 +881,10 @@ static int sctp_inet6_bind_verify(struct net = sock_net(&opt->inet.sk); rcu_read_lock(); dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); - if (!dev || - !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) { + if (!dev || !(opt->inet.freebind || + net->ipv6.sysctl.ip_nonlocal_bind || + ipv6_chk_addr(net, &addr->v6.sin6_addr, + dev, 0))) { rcu_read_unlock(); return 0; }

Patches currently in stable-queue which might be from laszlth@gmail.com are

queue-4.9/sctp-full-support-for-ipv6-ip_nonlocal_bind-ip_freebind.patch