net, ipv4, ipv6: Correct assignment of skb->network_header to skb->tail
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 however skb->network_header is now
an offset.
This patch corrects the problem by adding a wrapper to return skb tail as
an offset regardless of the value of NET_SKBUFF_DATA_USES_OFFSET. It seems
that skb->tail that this offset may be more than 64k and some care has been
taken to treat such cases as an error.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 8f2b830..5f93119 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1391,6 +1391,11 @@
skb_reset_tail_pointer(skb);
skb->tail += offset;
}
+
+static inline unsigned long skb_tail_offset(const struct sk_buff *skb)
+{
+ return skb->tail;
+}
#else /* NET_SKBUFF_DATA_USES_OFFSET */
static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
{
@@ -1407,6 +1412,10 @@
skb->tail = skb->data + offset;
}
+static inline unsigned long skb_tail_offset(const struct sk_buff *skb)
+{
+ return skb->tail - skb->head;
+}
#endif /* NET_SKBUFF_DATA_USES_OFFSET */
/*
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 37deedd..688517c 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -676,6 +676,8 @@
spin_lock_irqsave(&npinfo->rx_lock, flags);
list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
+ unsigned long tail_offset;
+
if (!ipv6_addr_equal(daddr, &np->local_ip.in6))
continue;
@@ -700,7 +702,12 @@
hdr->saddr = *saddr;
hdr->daddr = *daddr;
- send_skb->transport_header = send_skb->tail;
+ tail_offset = skb_tail_offset(skb);
+ if (tail_offset > 0xffff) {
+ kfree_skb(send_skb);
+ continue;
+ }
+ skb_set_network_header(send_skb, tail_offset);
skb_put(send_skb, size);
icmp6h = (struct icmp6hdr *)skb_transport_header(skb);
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 795498f..d2ede89 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2642,6 +2642,7 @@
__be16 *svlan_tci = NULL; /* Encapsulates priority and SVLAN ID */
__be16 *svlan_encapsulated_proto = NULL; /* packet type ID field (or len) for SVLAN tag */
u16 queue_map;
+ unsigned long tail_offset;
if (pkt_dev->nr_labels)
protocol = htons(ETH_P_MPLS_UC);
@@ -2708,7 +2709,12 @@
*vlan_encapsulated_proto = htons(ETH_P_IP);
}
- skb->network_header = skb->tail;
+ tail_offset = skb_tail_offset(skb);
+ if (tail_offset > 0xffff) {
+ kfree_skb(skb);
+ return NULL;
+ }
+ skb_set_network_header(skb, tail_offset);
skb->transport_header = skb->network_header + sizeof(struct iphdr);
skb_put(skb, sizeof(struct iphdr) + sizeof(struct udphdr));
skb_set_queue_mapping(skb, queue_map);
@@ -2775,6 +2781,7 @@
__be16 *svlan_tci = NULL; /* Encapsulates priority and SVLAN ID */
__be16 *svlan_encapsulated_proto = NULL; /* packet type ID field (or len) for SVLAN tag */
u16 queue_map;
+ unsigned long tail_offset;
if (pkt_dev->nr_labels)
protocol = htons(ETH_P_MPLS_UC);
@@ -2822,7 +2829,12 @@
*vlan_encapsulated_proto = htons(ETH_P_IPV6);
}
- skb->network_header = skb->tail;
+ tail_offset = skb_tail_offset(skb);
+ if (tail_offset > 0xffff) {
+ kfree_skb(skb);
+ return NULL;
+ }
+ skb_set_network_header(skb, tail_offset);
skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
skb_put(skb, sizeof(struct ipv6hdr) + sizeof(struct udphdr));
skb_set_queue_mapping(skb, queue_map);
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index f975399..df97f0a 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -945,6 +945,7 @@
struct igmpmsg *msg;
struct sock *mroute_sk;
int ret;
+ unsigned long tail_offset;
#ifdef CONFIG_IP_PIMSM
if (assert == IGMPMSG_WHOLEPKT)
@@ -980,7 +981,12 @@
/* Copy the IP header */
- skb->network_header = skb->tail;
+ tail_offset = skb_tail_offset(skb);
+ if (tail_offset > 0xffff) {
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+ skb_set_network_header(skb, tail_offset);
skb_put(skb, ihl);
skb_copy_to_linear_data(skb, pkt->data, ihl);
ip_hdr(skb)->protocol = 0; /* Flag to the kernel this is a route add */