4.13-stable review patch. If anyone has any objections, please let me know.
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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 @@ -882,8 +882,10 @@ 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; }