Commit ccc2d97c authored May 06, 2010 by Bjørn Mork Committed by David S. Miller May 06, 2010

ipv4: udp: fix short packet and bad checksum logging



commit 2783ef23 moved the initialisation of saddr and daddr after
pskb_may_pull() to avoid a potential data corruption.  Unfortunately
also placing it after the short packet and bad checksum error paths,
where these variables are used for logging.  The result is bogus
output like

[92238.389505] UDP: short packet: From 2.0.0.0:65535 23715/178 to 0.0.0.0:65535

Moving the saddr and daddr initialisation above the error paths, while still
keeping it after the pskb_may_pull() to keep the fix from commit 2783ef23.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Cc: stable@kernel.org
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 80ea76bb

net/ipv4/udp.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -1527,6 +1527,9 @@ int __udp4_lib_rcv(struct sk_buff skb, struct udp_table udptable,

		uh = udp_hdr(skb);
		ulen = ntohs(uh->len);
		saddr = ip_hdr(skb)->saddr;
		daddr = ip_hdr(skb)->daddr;

		if (ulen > skb->len)
		goto short_packet;

		@@ -1540,9 +1543,6 @@ int __udp4_lib_rcv(struct sk_buff skb, struct udp_table udptable,
		if (udp4_csum_init(skb, uh, proto))
		goto csum_error;

		saddr = ip_hdr(skb)->saddr;
		daddr = ip_hdr(skb)->daddr;

		if (rt->rt_flags & (RTCF_BROADCAST\|RTCF_MULTICAST))
		return __udp4_lib_mcast_deliver(net, skb, uh,
		saddr, daddr, udptable);