gre: fix TUNNEL_SEQ bit check on sequence numbering

The current logic of flags | TUNNEL_SEQ is always non-zero and hence
sequence numbers are always incremented no matter the setting of the
TUNNEL_SEQ bit.  Fix this by using & instead of |.

Detected by CoverityScan, CID#1466039 ("Operands don't affect result")

Fixes: 77a5196a804e ("gre: add sequence number for collect md mode.")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 2fa2ef2..9ab1aa2 100644 (file)
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -550,7 +550,7 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
                (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
        gre_build_header(skb, tunnel_hlen, flags, proto,
                         tunnel_id_to_key32(tun_info->key.tun_id),
-                        (flags | TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0);
+                        (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0);
 
        df = key->tun_flags & TUNNEL_DONT_FRAGMENT ?  htons(IP_DF) : 0;
 

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 7d8775c..6adbcf4 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -724,7 +724,7 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
                gre_build_header(skb, tunnel->tun_hlen,
                                 flags, protocol,
                                 tunnel_id_to_key32(tun_info->key.tun_id),
-                                (flags | TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
+                                (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
                                                      : 0);
 
        } else {