[ 04/46] macvlan: validate flags

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: "Michael S. Tsirkin" <mst@redhat.com>

[ Upstream commit 1512747820367c8b3b8b72035f0f78c62f2bf1e9 ]

commit df8ef8f3aaa6692970a436204c4429210addb23a
    macvlan: add FDB bridge ops and macvlan flags
added a flags field to macvlan, which can be
controlled from userspace.
The idea is to make the interface future-proof
so we can add flags and not new fields.

However, flags value isn't validated, as a result,
userspace can't detect which flags are supported.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/macvlan.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -727,6 +727,10 @@ static int macvlan_validate(struct nlatt
 			return -EADDRNOTAVAIL;
 	}
 
+	if (data && data[IFLA_MACVLAN_FLAGS] &&
+	    nla_get_u16(data[IFLA_MACVLAN_FLAGS]) & ~MACVLAN_FLAG_NOPROMISC)
+		return -EINVAL;
+
 	if (data && data[IFLA_MACVLAN_MODE]) {
 		switch (nla_get_u32(data[IFLA_MACVLAN_MODE])) {
 		case MACVLAN_MODE_PRIVATE: