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| author | Al Viro <viro@zeniv.linux.org.uk> | 2006-09-19 22:23:19 +0200 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-09-23 00:19:43 +0200 |
| commit | c55e2f4997a104d66b59bdf1aa8ab125d09ae00a (patch) | |
| tree | 51c92b1085e5a3067a14386c0b449ac33036bb7a /net/ipv4/ip_gre.c | |
| parent | [DCCP] CCID2: Add helper functions for changing important CCID2 state (diff) | |
| download | linux-c55e2f4997a104d66b59bdf1aa8ab125d09ae00a.tar.xz linux-c55e2f4997a104d66b59bdf1aa8ab125d09ae00a.zip | |
[IPV4]: ipip and ip_gre encapsulation bugs
Handling of ipip and ip_gre ICMP error relaying is b0rken; it accesses
8bit field + 3 reserved octets as host-endian 32bit, does comparison,
subtraction and stuffs the result back. That breaks on big-endian.
Fixed, made endian-clean.
[ Note that this effected code is permanently commented out with
and ifdef, so this error couldn't actually cause problems for
anyone. -DaveM ]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_gre.c')
| -rw-r--r-- | net/ipv4/ip_gre.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index e66f6ff2e198..f5fba051df3d 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -393,7 +393,8 @@ out: int code = skb->h.icmph->code; int rel_type = 0; int rel_code = 0; - int rel_info = 0; + __be32 rel_info = 0; + __u32 n = 0; u16 flags; int grehlen = (iph->ihl<<2) + 4; struct sk_buff *skb2; @@ -422,14 +423,16 @@ out: default: return; case ICMP_PARAMETERPROB: - if (skb->h.icmph->un.gateway < (iph->ihl<<2)) + n = ntohl(skb->h.icmph->un.gateway) >> 24; + if (n < (iph->ihl<<2)) return; /* So... This guy found something strange INSIDE encapsulated packet. Well, he is fool, but what can we do ? */ rel_type = ICMP_PARAMETERPROB; - rel_info = skb->h.icmph->un.gateway - grehlen; + n -= grehlen; + rel_info = htonl(n << 24); break; case ICMP_DEST_UNREACH: @@ -440,13 +443,14 @@ out: return; case ICMP_FRAG_NEEDED: /* And it is the only really necessary thing :-) */ - rel_info = ntohs(skb->h.icmph->un.frag.mtu); - if (rel_info < grehlen+68) + n = ntohs(skb->h.icmph->un.frag.mtu); + if (n < grehlen+68) return; - rel_info -= grehlen; + n -= grehlen; /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */ - if (rel_info > ntohs(eiph->tot_len)) + if (n > ntohs(eiph->tot_len)) return; + rel_info = htonl(n); break; default: /* All others are translated to HOST_UNREACH. @@ -508,12 +512,11 @@ out: /* change mtu on this route */ if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { - if (rel_info > dst_mtu(skb2->dst)) { + if (n > dst_mtu(skb2->dst)) { kfree_skb(skb2); return; } - skb2->dst->ops->update_pmtu(skb2->dst, rel_info); - rel_info = htonl(rel_info); + skb2->dst->ops->update_pmtu(skb2->dst, n); } else if (type == ICMP_TIME_EXCEEDED) { struct ip_tunnel *t = netdev_priv(skb2->dev); if (t->parms.iph.ttl) { |