From: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxx> Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx> --- 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 37bf943..afc4ab7 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 -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
