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Commit ab43ed8b authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
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ipv4: raw: fix icmp_filter() 



icmp_filter() should not modify its input, or else its caller
would need to recompute ip_hdr() if skb->head is reallocated.

Use skb_header_pointer() instead of pskb_may_pull() and
change the prototype to make clear both sk and skb are const.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9913b8c8

net/ipv4/raw.c

+8 −6
Original line number Diff line number Diff line
@@ -131,18 +131,20 @@ static struct sock *__raw_v4_lookup(struct net *net, struct sock *sk, 
 *	0 - deliver

 *	1 - block

 */

static __inline__ int icmp_filter(struct sock *sk, struct sk_buff *skb)

static int icmp_filter(const struct sock *sk, const struct sk_buff *skb)

{

	int type;

	struct icmphdr _hdr;

	const struct icmphdr *hdr;



	if (!pskb_may_pull(skb, sizeof(struct icmphdr)))

	hdr = skb_header_pointer(skb, skb_transport_offset(skb),

				 sizeof(_hdr), &_hdr);

	if (!hdr)

		return 1;



	type = icmp_hdr(skb)->type;

	if (type < 32) {

	if (hdr->type < 32) {

		__u32 data = raw_sk(sk)->filter.data;



		return ((1 << type) & data) != 0;

		return ((1U << hdr->type) & data) != 0;

	}



	/* Do not block unknown ICMP types */