diff options
| author | Wei Yongjun <yjwei@cn.fujitsu.com> | 2008-07-26 11:59:10 +0100 |
|---|---|---|
| committer | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2008-07-26 11:59:10 +0100 |
| commit | 18e1d836002ad970f42736bad09b7be9cfe99545 (patch) | |
| tree | 2e704da1e24eba0f1a09d4b983a34bcc5b51f29d /net/dccp | |
| parent | e0bcfb0c6a6ed9ebd68746b306298dc5797fd426 (diff) | |
| download | lwn-18e1d836002ad970f42736bad09b7be9cfe99545.tar.gz lwn-18e1d836002ad970f42736bad09b7be9cfe99545.zip | |
dccp: Fix incorrect length check for ICMPv4 packets
Unlike TCP, which only needs 8 octets of original packet data, DCCP requires
minimally 12 or 16 bytes for ICMP-payload sequence number checks.
This patch replaces the insufficient length constant of 8 with a two-stage
test, making sure that 12 bytes are available, before computing the basic
header length required for sequence number checks.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Diffstat (limited to 'net/dccp')
| -rw-r--r-- | net/dccp/ipv4.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index 6a2f1879e183..882c5c4de69e 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -196,8 +196,8 @@ static inline void dccp_do_pmtu_discovery(struct sock *sk, static void dccp_v4_err(struct sk_buff *skb, u32 info) { const struct iphdr *iph = (struct iphdr *)skb->data; - const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + - (iph->ihl << 2)); + const u8 offset = iph->ihl << 2; + const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset); struct dccp_sock *dp; struct inet_sock *inet; const int type = icmp_hdr(skb)->type; @@ -207,7 +207,8 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info) int err; struct net *net = dev_net(skb->dev); - if (skb->len < (iph->ihl << 2) + 8) { + if (skb->len < offset + sizeof(*dh) || + skb->len < offset + __dccp_basic_hdr_len(dh)) { ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); return; } |