Commit daeb6a8f authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

ipv4: icmp: do not process ICMP_EXT_ECHOREPLY for broadcast/multicast addresses 



There is no point processing ICMP_EXT_ECHOREPLY for routes
which would drop ICMP_ECHOREPLY (RFC 1122 3.2.2.6, 3.2.2.8)

This seems an oversight of the initial implementation.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250226183437.1457318-2-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 8e7e3d97

net/ipv4/icmp.c

+16 −16
Original line number Diff line number Diff line
@@ -1248,22 +1248,6 @@ int icmp_rcv(struct sk_buff *skb) 
		goto reason_check;

	}



	if (icmph->type == ICMP_EXT_ECHOREPLY) {

		reason = ping_rcv(skb);

		goto reason_check;

	}



	/*

	 *	18 is the highest 'known' ICMP type. Anything else is a mystery

	 *

	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently

	 *		  discarded.

	 */

	if (icmph->type > NR_ICMP_TYPES) {

		reason = SKB_DROP_REASON_UNHANDLED_PROTO;

		goto error;

	}



	/*

	 *	Parse the ICMP message

	 */
@@ -1290,6 +1274,22 @@ int icmp_rcv(struct sk_buff *skb) 
		}

	}



	if (icmph->type == ICMP_EXT_ECHOREPLY) {

		reason = ping_rcv(skb);

		goto reason_check;

	}



	/*

	 *	18 is the highest 'known' ICMP type. Anything else is a mystery

	 *

	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently

	 *		  discarded.

	 */

	if (icmph->type > NR_ICMP_TYPES) {

		reason = SKB_DROP_REASON_UNHANDLED_PROTO;

		goto error;

	}



	reason = icmp_pointers[icmph->type].handler(skb);

reason_check:

	if (!reason)  {