diff options
| author | Patrick McHardy <kaber@trash.net> | 2013-09-30 08:51:46 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2013-09-30 12:44:38 +0200 |
| commit | f4a87e7bd2eaef26a3ca25437ce8b807de2966ad (patch) | |
| tree | 72359689d53c3ce656b4568f04b8ee92dd2e05f4 /include | |
| parent | d1ee4fea0b6946dd8bc61b46db35ea80af7af34b (diff) | |
netfilter: synproxy: fix BUG_ON triggered by corrupt TCP packets
TCP packets hitting the SYN proxy through the SYNPROXY target are not
validated by TCP conntrack. When th->doff is below 5, an underflow happens
when calculating the options length, causing skb_header_pointer() to
return NULL and triggering the BUG_ON().
Handle this case gracefully by checking for NULL instead of using BUG_ON().
Reported-by: Martin Topholm <mph@one.com>
Tested-by: Martin Topholm <mph@one.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/netfilter/nf_conntrack_synproxy.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/netfilter/nf_conntrack_synproxy.h b/include/net/netfilter/nf_conntrack_synproxy.h index 806f54a290d..f572f313d6f 100644 --- a/include/net/netfilter/nf_conntrack_synproxy.h +++ b/include/net/netfilter/nf_conntrack_synproxy.h @@ -56,7 +56,7 @@ struct synproxy_options { struct tcphdr; struct xt_synproxy_info; -extern void synproxy_parse_options(const struct sk_buff *skb, unsigned int doff, +extern bool synproxy_parse_options(const struct sk_buff *skb, unsigned int doff, const struct tcphdr *th, struct synproxy_options *opts); extern unsigned int synproxy_options_size(const struct synproxy_options *opts); |