From 7cc461900549fc480eb133948649a1edb7eaaa6f Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Tue, 28 May 2013 20:34:29 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- include/linux/skbuff.h | 9 +++++++++ net/core/netpoll.c | 9 ++++++++- net/core/pktgen.c | 16 ++++++++++++++-- net/ipv4/ipmr.c | 8 +++++++- 4 files changed, 38 insertions(+), 4 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 8f2b830772a8..5f931191cf57 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1391,6 +1391,11 @@ static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 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 @@ static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 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 37deedd48bcc..688517c7ff17 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -676,6 +676,8 @@ static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo 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 @@ static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo 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 795498fd4587..d2ede89662be 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -2642,6 +2642,7 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev, __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 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev, *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 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev, __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 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev, *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 f975399f3522..df97f0ac1a1c 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -945,6 +945,7 @@ static int ipmr_cache_report(struct mr_table *mrt, 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 @@ static int ipmr_cache_report(struct mr_table *mrt, /* 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 */ -- 2.20.1