4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Laszlo Toth <laszlth@xxxxxxxxx>
[ 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@xxxxxxxxx>
Reviewed-by: Xin Long <lucien.xin@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
}