openvswitch: packet messages need their own probe attribtue

User space is currently sending a OVS_FLOW_ATTR_PROBE for both flow
and packet messages. This leads to an out-of-bounds access in
ovs_packet_cmd_execute() because OVS_FLOW_ATTR_PROBE >
OVS_PACKET_ATTR_MAX.

Introduce a new OVS_PACKET_ATTR_PROBE with the same numeric value
as OVS_FLOW_ATTR_PROBE to grow the range of accepted packet attributes
while maintaining to be binary compatible with existing OVS binaries.

Fixes: 05da589 ("openvswitch: Add support for OVS_FLOW_ATTR_PROBE.")
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Tracked-down-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Jesse Gross <jesse@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 1 deletions

diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index 3a6dcaa359b7..f714e8633352 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -174,6 +174,10 @@ enum ovs_packet_attr {
         OVS_PACKET_ATTR_USERDATA,    /* OVS_ACTION_ATTR_USERSPACE arg. */
         OVS_PACKET_ATTR_EGRESS_TUN_KEY,  /* Nested OVS_TUNNEL_KEY_ATTR_*
                                             attributes. */
+        OVS_PACKET_ATTR_UNUSED1,
+        OVS_PACKET_ATTR_UNUSED2,
+        OVS_PACKET_ATTR_PROBE,      /* Packet operation is a feature probe,
+                                       error logging should be suppressed. */
         __OVS_PACKET_ATTR_MAX
 };
 
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 4e9a5f035cbc..b07349e82d78 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -524,7 +524,7 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
         struct vport *input_vport;
         int len;
         int err;
-        bool log = !a[OVS_FLOW_ATTR_PROBE];
+        bool log = !a[OVS_PACKET_ATTR_PROBE];
 
         err = -EINVAL;
         if (!a[OVS_PACKET_ATTR_PACKET] || !a[OVS_PACKET_ATTR_KEY] ||
@@ -610,6 +610,7 @@ static const struct nla_policy packet_policy[OVS_PACKET_ATTR_MAX + 1] = {
         [OVS_PACKET_ATTR_PACKET] = { .len = ETH_HLEN },
         [OVS_PACKET_ATTR_KEY] = { .type = NLA_NESTED },
         [OVS_PACKET_ATTR_ACTIONS] = { .type = NLA_NESTED },
+        [OVS_PACKET_ATTR_PROBE] = { .type = NLA_FLAG },
 };
 
 static const struct genl_ops dp_packet_genl_ops[] = {