[NETFILTER]: nf_conntrack_tcp: catch invalid state updates over ctnetlink
Invalid states can cause out-of-bound memory accesses of the state table.
Also don't insist on having a new state contained in the netlink message.
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 6256795..57831c7 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -1129,11 +1129,13 @@
if (err < 0)
return err;
- if (!tb[CTA_PROTOINFO_TCP_STATE])
+ if (tb[CTA_PROTOINFO_TCP_STATE] &&
+ nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]) >= TCP_CONNTRACK_MAX)
return -EINVAL;
write_lock_bh(&tcp_lock);
- ct->proto.tcp.state = nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]);
+ if (tb[CTA_PROTOINFO_TCP_STATE])
+ ct->proto.tcp.state = nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]);
if (tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]) {
struct nf_ct_tcp_flags *attr =