Commit 29a3cad5 authored by Simon Horman's avatar Simon Horman Committed by David S. Miller
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ipv6: Correct comparisons and calculations using skb->tail and skb-transport_header 



This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer whereas skb->transport_header
will be an offset from head. This is corrected by using wrappers that
ensure that comparisons and calculations are always made using pointers.

Signed-off-by: default avatarSimon Horman <horms@verge.net.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ced14f68

net/ipv6/exthdrs_core.c

+1 −1
Original line number Diff line number Diff line
@@ -115,7 +115,7 @@ EXPORT_SYMBOL(ipv6_skip_exthdr); 
int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)

{

	const unsigned char *nh = skb_network_header(skb);

	int packet_len = skb->tail - skb->network_header;

	int packet_len = skb_tail_pointer(skb) - skb_network_header(skb);

	struct ipv6_opt_hdr *hdr;

	int len;

net/ipv6/icmp.c

+1 −1
Original line number Diff line number Diff line
@@ -399,7 +399,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) 
	int err = 0;



	if ((u8 *)hdr < skb->head ||

	    (skb->network_header + sizeof(*hdr)) > skb->tail)

	    (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))

		return;



	/*

net/ipv6/mcast.c

+3 −2
Original line number Diff line number Diff line
@@ -1409,8 +1409,9 @@ static void mld_sendpack(struct sk_buff *skb) 
	idev = __in6_dev_get(skb->dev);

	IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);



	payload_len = (skb->tail - skb->network_header) - sizeof(*pip6);

	mldlen = skb->tail - skb->transport_header;

	payload_len = (skb_tail_pointer(skb) - skb_network_header(skb)) -

		sizeof(*pip6);

	mldlen = skb_tail_pointer(skb) - skb_transport_header(skb);

	pip6->payload_len = htons(payload_len);



	pmr->mld2r_cksum = csum_ipv6_magic(&pip6->saddr, &pip6->daddr, mldlen,

net/ipv6/mip6.c

+4 −2
Original line number Diff line number Diff line
@@ -268,7 +268,8 @@ static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb, 
	struct ipv6_opt_hdr *exthdr =

				   (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);

	const unsigned char *nh = skb_network_header(skb);

	unsigned int packet_len = skb->tail - skb->network_header;

	unsigned int packet_len = skb_tail_pointer(skb) -

		skb_network_header(skb);

	int found_rhdr = 0;



	*nexthdr = &ipv6_hdr(skb)->nexthdr;
@@ -404,7 +405,8 @@ static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb, 
	struct ipv6_opt_hdr *exthdr =

				   (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);

	const unsigned char *nh = skb_network_header(skb);

	unsigned int packet_len = skb->tail - skb->network_header;

	unsigned int packet_len = skb_tail_pointer(skb) -

		skb_network_header(skb);

	int found_rhdr = 0;



	*nexthdr = &ipv6_hdr(skb)->nexthdr;

net/ipv6/ndisc.c

+5 −4
Original line number Diff line number Diff line
@@ -693,7 +693,7 @@ static void ndisc_recv_ns(struct sk_buff *skb) 
	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;

	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;

	u8 *lladdr = NULL;

	u32 ndoptlen = skb->tail - (skb->transport_header +

	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +

				    offsetof(struct nd_msg, opt));

	struct ndisc_options ndopts;

	struct net_device *dev = skb->dev;
@@ -853,7 +853,7 @@ static void ndisc_recv_na(struct sk_buff *skb) 
	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;

	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;

	u8 *lladdr = NULL;

	u32 ndoptlen = skb->tail - (skb->transport_header +

	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +

				    offsetof(struct nd_msg, opt));

	struct ndisc_options ndopts;

	struct net_device *dev = skb->dev;
@@ -1069,7 +1069,8 @@ static void ndisc_router_discovery(struct sk_buff *skb) 


	__u8 * opt = (__u8 *)(ra_msg + 1);



	optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);

	optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -

		sizeof(struct ra_msg);



	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {

		ND_PRINTK(2, warn, "RA: source address is not link-local\n");
@@ -1346,7 +1347,7 @@ static void ndisc_redirect_rcv(struct sk_buff *skb) 
	u8 *hdr;

	struct ndisc_options ndopts;

	struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);

	u32 ndoptlen = skb->tail - (skb->transport_header +

	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +

				    offsetof(struct rd_msg, opt));



#ifdef CONFIG_IPV6_NDISC_NODETYPE

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