Commit 3b233fe0 authored Jun 27, 2013 by Daniel Borkmann Committed by David S. Miller Jun 28, 2013

nlmon: fix comparison in nlmon_is_valid_mtu



This patch fixes the following warning introduced in e4fc408e
("packet: nlmon: virtual netlink monitoring device for packet
sockets") reported by Dan Carpenter:

warning: "drivers/net/nlmon.c:31 nlmon_is_valid_mtu()
	 warn: always true condition '(new_mtu <= ((~0 >> 1))) =>
				      (s32min-s32max <= s32max)'"

Thus, we should simply remove the test against INT_MAX. Next to that
we also need to explicitly cast the sizeof() case as the comparison
is type promoted to unsigned long so negative values are then
valid instead of invalid. While at it, this also adds a comment about
Netlink and MTUs.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent cf6122be

drivers/net/nlmon.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -28,7 +28,11 @@ static netdev_tx_t nlmon_xmit(struct sk_buff skb, struct net_device dev)

		static int nlmon_is_valid_mtu(int new_mtu)
		{
		return new_mtu >= sizeof(struct nlmsghdr) && new_mtu <= INT_MAX;
		/* Note that in netlink we do not really have an upper limit. On
		* default, we use NLMSG_GOODSIZE. Here at least we should make
		* sure that it's at least the header size.
		*/
		return new_mtu >= (int) sizeof(struct nlmsghdr);
		}

		static int nlmon_change_mtu(struct net_device *dev, int new_mtu)