4.16-stable review patch. If anyone has any objections, please let me know.
------------------ From: Paolo Abeni <[email protected]> [ Upstream commit 69678bcd4d2dedbc3e8fcd6d7d99f283d83c531a ] Damir reported a breakage of SO_BINDTODEVICE for UDP sockets. In absence of VRF devices, after commit fb74c27735f0 ("net: ipv4: add second dif to udp socket lookups") the dif mismatch isn't fatal anymore for UDP socket lookup with non null sk_bound_dev_if, breaking SO_BINDTODEVICE semantics. This changeset addresses the issue making the dif match mandatory again in the above scenario. Reported-by: Damir Mansurov <[email protected]> Fixes: fb74c27735f0 ("net: ipv4: add second dif to udp socket lookups") Fixes: 1801b570dd2a ("net: ipv6: add second dif to udp socket lookups") Signed-off-by: Paolo Abeni <[email protected]> Acked-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- net/ipv4/udp.c | 4 ++-- net/ipv6/udp.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -407,9 +407,9 @@ static int compute_score(struct sock *sk bool dev_match = (sk->sk_bound_dev_if == dif || sk->sk_bound_dev_if == sdif); - if (exact_dif && !dev_match) + if (!dev_match) return -1; - if (sk->sk_bound_dev_if && dev_match) + if (sk->sk_bound_dev_if) score += 4; } --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -148,9 +148,9 @@ static int compute_score(struct sock *sk bool dev_match = (sk->sk_bound_dev_if == dif || sk->sk_bound_dev_if == sdif); - if (exact_dif && !dev_match) + if (!dev_match) return -1; - if (sk->sk_bound_dev_if && dev_match) + if (sk->sk_bound_dev_if) score++; }
