From: Kuniyuki Iwashima kuniyu@amazon.co.jp
[ Upstream commit f2b2c55e512879a05456eaf5de4d1ed2f7757509 ]
If an unconnected socket in a UDP reuseport group connect()s, has_conns is set to 1. Then, when a packet is received, udp[46]_lib_lookup2() scans all sockets in udp_hslot looking for the connected socket with the highest score.
However, when the number of sockets bound to the port exceeds max_socks, reuseport_grow() resets has_conns to 0. It can cause udp[46]_lib_lookup2() to return without scanning all sockets, resulting in that packets sent to connected sockets may be distributed to unconnected sockets.
Therefore, reuseport_grow() should copy has_conns.
Fixes: acdcecc61285 ("udp: correct reuseport selection with connected sockets") CC: Willem de Bruijn willemb@google.com Reviewed-by: Benjamin Herrenschmidt benh@amazon.com Signed-off-by: Kuniyuki Iwashima kuniyu@amazon.co.jp Acked-by: Willem de Bruijn willemb@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/sock_reuseport.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/core/sock_reuseport.c +++ b/net/core/sock_reuseport.c @@ -112,6 +112,7 @@ static struct sock_reuseport *reuseport_ more_reuse->prog = reuse->prog; more_reuse->reuseport_id = reuse->reuseport_id; more_reuse->bind_inany = reuse->bind_inany; + more_reuse->has_conns = reuse->has_conns;
memcpy(more_reuse->socks, reuse->socks, reuse->num_socks * sizeof(struct sock *));