bpf: clear the ip_tunnel_info.

The percpu metadata_dst might carry the stale ip_tunnel_info
and cause incorrect behavior.  When mixing tests using ipv4/ipv6
bpf vxlan and geneve tunnel, the ipv6 tunnel info incorrectly uses
ipv4's src ip addr as its ipv6 src address, because the previous
tunnel info does not clean up.  The patch zeros the fields in
ip_tunnel_info.

Signed-off-by: William Tu <u9012063@gmail.com>
Reported-by: Yifeng Sun <pkusunyifeng@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/net/core/filter.c b/net/core/filter.c
index d31aff93270d0e27ace3aa39e84d73a385f2e05a..e77c30ca491df723bacf923ac2f328cc50a580b0 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3240,6 +3240,7 @@ BPF_CALL_4(bpf_skb_set_tunnel_key, struct sk_buff *, skb,
        skb_dst_set(skb, (struct dst_entry *) md);
 
        info = &md->u.tun_info;
+       memset(info, 0, sizeof(*info));
        info->mode = IP_TUNNEL_INFO_TX;
 
        info->key.tun_flags = TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_NOCACHE;