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| author | Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> | 2011-08-30 15:45:10 +0200 |
|---|---|---|
| committer | Patrick McHardy <kaber@trash.net> | 2011-08-30 15:45:10 +0200 |
| commit | 4a5cc84ae7e19fb7a72a30332ba67af43e0ad1ad (patch) | |
| tree | b6ed9ec59814bfdacbdbd87cd24bccc08c54e5ae | |
| parent | 4c6e4209662b2a4147cde16c2144a253a7430a49 (diff) | |
| download | lwn-4a5cc84ae7e19fb7a72a30332ba67af43e0ad1ad.tar.gz lwn-4a5cc84ae7e19fb7a72a30332ba67af43e0ad1ad.zip | |
netfilter: nf_ct_tcp: fix incorrect handling of invalid TCP option
Michael M. Builov reported that in the tcp_options and tcp_sack functions
of netfilter TCP conntrack the incorrect handling of invalid TCP option
with too big opsize may lead to read access beyond tcp-packet or buffer
allocated on stack (netfilter bugzilla #738). The fix is to stop parsing
the options at detecting the broken option.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
| -rw-r--r-- | net/netfilter/nf_conntrack_proto_tcp.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c index 37bf94394be0..afc4ab7cfe01 100644 --- a/net/netfilter/nf_conntrack_proto_tcp.c +++ b/net/netfilter/nf_conntrack_proto_tcp.c @@ -409,7 +409,7 @@ static void tcp_options(const struct sk_buff *skb, if (opsize < 2) /* "silly options" */ return; if (opsize > length) - break; /* don't parse partial options */ + return; /* don't parse partial options */ if (opcode == TCPOPT_SACK_PERM && opsize == TCPOLEN_SACK_PERM) @@ -469,7 +469,7 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff, if (opsize < 2) /* "silly options" */ return; if (opsize > length) - break; /* don't parse partial options */ + return; /* don't parse partial options */ if (opcode == TCPOPT_SACK && opsize >= (TCPOLEN_SACK_BASE |