cls_flow: add sanity check for the packet length

The packet length should be checked before the packet data is dereferenced.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Changli Gao 2010-08-04 04:48:12 +00:00 committed by David S. Miller
parent f9599ce111
commit 4b95c3d40d
1 changed files with 56 additions and 40 deletions

View File

@ -65,37 +65,47 @@ static inline u32 addr_fold(void *addr)
return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0); return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
} }
static u32 flow_get_src(const struct sk_buff *skb) static u32 flow_get_src(struct sk_buff *skb)
{ {
switch (skb->protocol) { switch (skb->protocol) {
case htons(ETH_P_IP): case htons(ETH_P_IP):
if (pskb_network_may_pull(skb, sizeof(struct iphdr)))
return ntohl(ip_hdr(skb)->saddr); return ntohl(ip_hdr(skb)->saddr);
break;
case htons(ETH_P_IPV6): case htons(ETH_P_IPV6):
if (pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
return ntohl(ipv6_hdr(skb)->saddr.s6_addr32[3]); return ntohl(ipv6_hdr(skb)->saddr.s6_addr32[3]);
default: break;
}
return addr_fold(skb->sk); return addr_fold(skb->sk);
} }
}
static u32 flow_get_dst(const struct sk_buff *skb) static u32 flow_get_dst(struct sk_buff *skb)
{ {
switch (skb->protocol) { switch (skb->protocol) {
case htons(ETH_P_IP): case htons(ETH_P_IP):
if (pskb_network_may_pull(skb, sizeof(struct iphdr)))
return ntohl(ip_hdr(skb)->daddr); return ntohl(ip_hdr(skb)->daddr);
break;
case htons(ETH_P_IPV6): case htons(ETH_P_IPV6):
if (pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
return ntohl(ipv6_hdr(skb)->daddr.s6_addr32[3]); return ntohl(ipv6_hdr(skb)->daddr.s6_addr32[3]);
default: break;
}
return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol; return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
} }
}
static u32 flow_get_proto(const struct sk_buff *skb) static u32 flow_get_proto(struct sk_buff *skb)
{ {
switch (skb->protocol) { switch (skb->protocol) {
case htons(ETH_P_IP): case htons(ETH_P_IP):
return ip_hdr(skb)->protocol; return pskb_network_may_pull(skb, sizeof(struct iphdr)) ?
ip_hdr(skb)->protocol : 0;
case htons(ETH_P_IPV6): case htons(ETH_P_IPV6):
return ipv6_hdr(skb)->nexthdr; return pskb_network_may_pull(skb, sizeof(struct ipv6hdr)) ?
ipv6_hdr(skb)->nexthdr : 0;
default: default:
return 0; return 0;
} }
@ -116,58 +126,64 @@ static int has_ports(u8 protocol)
} }
} }
static u32 flow_get_proto_src(const struct sk_buff *skb) static u32 flow_get_proto_src(struct sk_buff *skb)
{ {
u32 res = 0;
switch (skb->protocol) { switch (skb->protocol) {
case htons(ETH_P_IP): { case htons(ETH_P_IP): {
struct iphdr *iph = ip_hdr(skb); struct iphdr *iph;
if (!pskb_network_may_pull(skb, sizeof(*iph)))
break;
iph = ip_hdr(skb);
if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) && if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
has_ports(iph->protocol)) has_ports(iph->protocol) &&
res = ntohs(*(__be16 *)((void *)iph + iph->ihl * 4)); pskb_network_may_pull(skb, iph->ihl * 4 + 2))
return ntohs(*(__be16 *)((void *)iph + iph->ihl * 4));
break; break;
} }
case htons(ETH_P_IPV6): { case htons(ETH_P_IPV6): {
struct ipv6hdr *iph = ipv6_hdr(skb); struct ipv6hdr *iph;
if (!pskb_network_may_pull(skb, sizeof(*iph) + 2))
break;
iph = ipv6_hdr(skb);
if (has_ports(iph->nexthdr)) if (has_ports(iph->nexthdr))
res = ntohs(*(__be16 *)&iph[1]); return ntohs(*(__be16 *)&iph[1]);
break; break;
} }
default:
res = addr_fold(skb->sk);
} }
return res; return addr_fold(skb->sk);
} }
static u32 flow_get_proto_dst(const struct sk_buff *skb) static u32 flow_get_proto_dst(struct sk_buff *skb)
{ {
u32 res = 0;
switch (skb->protocol) { switch (skb->protocol) {
case htons(ETH_P_IP): { case htons(ETH_P_IP): {
struct iphdr *iph = ip_hdr(skb); struct iphdr *iph;
if (!pskb_network_may_pull(skb, sizeof(*iph)))
break;
iph = ip_hdr(skb);
if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) && if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
has_ports(iph->protocol)) has_ports(iph->protocol) &&
res = ntohs(*(__be16 *)((void *)iph + iph->ihl * 4 + 2)); pskb_network_may_pull(skb, iph->ihl * 4 + 4))
return ntohs(*(__be16 *)((void *)iph + iph->ihl * 4 + 2));
break; break;
} }
case htons(ETH_P_IPV6): { case htons(ETH_P_IPV6): {
struct ipv6hdr *iph = ipv6_hdr(skb); struct ipv6hdr *iph;
if (!pskb_network_may_pull(skb, sizeof(*iph) + 4))
break;
iph = ipv6_hdr(skb);
if (has_ports(iph->nexthdr)) if (has_ports(iph->nexthdr))
res = ntohs(*(__be16 *)((void *)&iph[1] + 2)); return ntohs(*(__be16 *)((void *)&iph[1] + 2));
break; break;
} }
default:
res = addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
} }
return res; return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
} }
static u32 flow_get_iif(const struct sk_buff *skb) static u32 flow_get_iif(const struct sk_buff *skb)
@ -211,7 +227,7 @@ static u32 flow_get_nfct(const struct sk_buff *skb)
}) })
#endif #endif
static u32 flow_get_nfct_src(const struct sk_buff *skb) static u32 flow_get_nfct_src(struct sk_buff *skb)
{ {
switch (skb->protocol) { switch (skb->protocol) {
case htons(ETH_P_IP): case htons(ETH_P_IP):
@ -223,7 +239,7 @@ fallback:
return flow_get_src(skb); return flow_get_src(skb);
} }
static u32 flow_get_nfct_dst(const struct sk_buff *skb) static u32 flow_get_nfct_dst(struct sk_buff *skb)
{ {
switch (skb->protocol) { switch (skb->protocol) {
case htons(ETH_P_IP): case htons(ETH_P_IP):
@ -235,14 +251,14 @@ fallback:
return flow_get_dst(skb); return flow_get_dst(skb);
} }
static u32 flow_get_nfct_proto_src(const struct sk_buff *skb) static u32 flow_get_nfct_proto_src(struct sk_buff *skb)
{ {
return ntohs(CTTUPLE(skb, src.u.all)); return ntohs(CTTUPLE(skb, src.u.all));
fallback: fallback:
return flow_get_proto_src(skb); return flow_get_proto_src(skb);
} }
static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb) static u32 flow_get_nfct_proto_dst(struct sk_buff *skb)
{ {
return ntohs(CTTUPLE(skb, dst.u.all)); return ntohs(CTTUPLE(skb, dst.u.all));
fallback: fallback:
@ -281,7 +297,7 @@ static u32 flow_get_vlan_tag(const struct sk_buff *skb)
return tag & VLAN_VID_MASK; return tag & VLAN_VID_MASK;
} }
static u32 flow_key_get(const struct sk_buff *skb, int key) static u32 flow_key_get(struct sk_buff *skb, int key)
{ {
switch (key) { switch (key) {
case FLOW_KEY_SRC: case FLOW_KEY_SRC: