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Commit 1cde6436 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso Committed by David S. Miller
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[NETFILTER]: ctnetlink: Fix expectaction mask dumping 



The expectation mask has some particularities that requires a different
handling. The protocol number fields can be set to non-valid protocols,
ie. l3num is set to 0xFFFF. Since that protocol does not exist, the mask
tuple will not be dumped. Moreover, this results in a kernel panic when
nf_conntrack accesses the array of protocol handlers, that is PF_MAX (0x1F)
long.

This patch introduces the function ctnetlink_exp_dump_mask, that correctly
dumps the expectation mask. Such function uses the l3num value from the
expectation tuple that is a valid layer 3 protocol number. The value of the
l3num mask isn't dumped since it is meaningless from the userspace side.

Thanks to Yasuyuki Kozakai and Patrick McHardy for the feedback.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 50b521aa

net/ipv4/netfilter/ip_conntrack_netlink.c

+55 −17
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
 * (C) 2001 by Jay Schulist <jschlst@samba.org>

 * (C) 2002-2005 by Harald Welte <laforge@gnumonks.org>

 * (C) 2003 by Patrick Mchardy <kaber@trash.net>

 * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>

 * (C) 2005-2006 by Pablo Neira Ayuso <pablo@eurodev.net>

 *

 * I've reworked this stuff to use attributes instead of conntrack 

 * structures. 5.44 am. I need more tea. --pablo 05/07/11.
@@ -53,20 +53,18 @@ static char __initdata version[] = "0.90"; 


static inline int

ctnetlink_dump_tuples_proto(struct sk_buff *skb, 

			    const struct ip_conntrack_tuple *tuple)

			    const struct ip_conntrack_tuple *tuple,

			    struct ip_conntrack_protocol *proto)

{

	struct ip_conntrack_protocol *proto;

	int ret = 0;

	struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);



	NFA_PUT(skb, CTA_PROTO_NUM, sizeof(u_int8_t), &tuple->dst.protonum);



	/* If no protocol helper is found, this function will return the

	 * generic protocol helper, so proto won't *ever* be NULL */

	proto = ip_conntrack_proto_find_get(tuple->dst.protonum);

	if (likely(proto->tuple_to_nfattr))

		ret = proto->tuple_to_nfattr(skb, tuple);

	

	ip_conntrack_proto_put(proto);

	NFA_NEST_END(skb, nest_parms);



	return ret;
@@ -75,27 +73,40 @@ ctnetlink_dump_tuples_proto(struct sk_buff *skb, 
}



static inline int

ctnetlink_dump_tuples(struct sk_buff *skb, 

ctnetlink_dump_tuples_ip(struct sk_buff *skb,

			 const struct ip_conntrack_tuple *tuple)

{

	struct nfattr *nest_parms;

	int ret;

	struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);

	

	nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);

	NFA_PUT(skb, CTA_IP_V4_SRC, sizeof(u_int32_t), &tuple->src.ip);

	NFA_PUT(skb, CTA_IP_V4_DST, sizeof(u_int32_t), &tuple->dst.ip);

	NFA_NEST_END(skb, nest_parms);



	nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);

	ret = ctnetlink_dump_tuples_proto(skb, tuple);

	NFA_NEST_END(skb, nest_parms);



	return ret;

	return 0;



nfattr_failure:

	return -1;

}



static inline int

ctnetlink_dump_tuples(struct sk_buff *skb,

		      const struct ip_conntrack_tuple *tuple)

{

	int ret;

	struct ip_conntrack_protocol *proto;



	ret = ctnetlink_dump_tuples_ip(skb, tuple);

	if (unlikely(ret < 0))

		return ret;



	proto = ip_conntrack_proto_find_get(tuple->dst.protonum);

	ret = ctnetlink_dump_tuples_proto(skb, tuple, proto);

	ip_conntrack_proto_put(proto);



	return ret;

}



static inline int

ctnetlink_dump_status(struct sk_buff *skb, const struct ip_conntrack *ct)

{
@@ -1134,6 +1145,33 @@ ctnetlink_exp_dump_tuple(struct sk_buff *skb, 
	return -1;

}			



static inline int

ctnetlink_exp_dump_mask(struct sk_buff *skb,

			const struct ip_conntrack_tuple *tuple,

			const struct ip_conntrack_tuple *mask)

{

	int ret;

	struct ip_conntrack_protocol *proto;

	struct nfattr *nest_parms = NFA_NEST(skb, CTA_EXPECT_MASK);



	ret = ctnetlink_dump_tuples_ip(skb, mask);

	if (unlikely(ret < 0))

		goto nfattr_failure;



	proto = ip_conntrack_proto_find_get(tuple->dst.protonum);

	ret = ctnetlink_dump_tuples_proto(skb, mask, proto);

	ip_conntrack_proto_put(proto);

	if (unlikely(ret < 0))

		goto nfattr_failure;



	NFA_NEST_END(skb, nest_parms);



	return 0;



nfattr_failure:

	return -1;

}



static inline int

ctnetlink_exp_dump_expect(struct sk_buff *skb,

                          const struct ip_conntrack_expect *exp)
@@ -1144,7 +1182,7 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb, 


	if (ctnetlink_exp_dump_tuple(skb, &exp->tuple, CTA_EXPECT_TUPLE) < 0)

		goto nfattr_failure;

	if (ctnetlink_exp_dump_tuple(skb, &exp->mask, CTA_EXPECT_MASK) < 0)

	if (ctnetlink_exp_dump_mask(skb, &exp->tuple, &exp->mask) < 0)

		goto nfattr_failure;

	if (ctnetlink_exp_dump_tuple(skb,

				 &master->tuplehash[IP_CT_DIR_ORIGINAL].tuple,

net/netfilter/nf_conntrack_netlink.c

+62 −22
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
 * (C) 2001 by Jay Schulist <jschlst@samba.org>

 * (C) 2002-2006 by Harald Welte <laforge@gnumonks.org>

 * (C) 2003 by Patrick Mchardy <kaber@trash.net>

 * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>

 * (C) 2005-2006 by Pablo Neira Ayuso <pablo@eurodev.net>

 *

 * I've reworked this stuff to use attributes instead of conntrack 

 * structures. 5.44 am. I need more tea. --pablo 05/07/11.
@@ -55,20 +55,18 @@ static char __initdata version[] = "0.93"; 


static inline int

ctnetlink_dump_tuples_proto(struct sk_buff *skb, 

			    const struct nf_conntrack_tuple *tuple)

			    const struct nf_conntrack_tuple *tuple,

			    struct nf_conntrack_protocol *proto)

{

	struct nf_conntrack_protocol *proto;

	int ret = 0;

	struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);



	NFA_PUT(skb, CTA_PROTO_NUM, sizeof(u_int8_t), &tuple->dst.protonum);



	/* If no protocol helper is found, this function will return the

	 * generic protocol helper, so proto won't *ever* be NULL */

	proto = nf_ct_proto_find_get(tuple->src.l3num, tuple->dst.protonum);

	if (likely(proto->tuple_to_nfattr))

		ret = proto->tuple_to_nfattr(skb, tuple);

	

	nf_ct_proto_put(proto);

	NFA_NEST_END(skb, nest_parms);



	return ret;
@@ -77,33 +75,44 @@ ctnetlink_dump_tuples_proto(struct sk_buff *skb, 
}



static inline int

ctnetlink_dump_tuples(struct sk_buff *skb, 

		      const struct nf_conntrack_tuple *tuple)

ctnetlink_dump_tuples_ip(struct sk_buff *skb,

			 const struct nf_conntrack_tuple *tuple,

			 struct nf_conntrack_l3proto *l3proto)

{

	struct nfattr *nest_parms;

	struct nf_conntrack_l3proto *l3proto;

	int ret = 0;

	struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);



	l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);

	

	nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);

	if (likely(l3proto->tuple_to_nfattr))

		ret = l3proto->tuple_to_nfattr(skb, tuple);



	NFA_NEST_END(skb, nest_parms);



	return ret;



nfattr_failure:

	return -1;

}



static inline int

ctnetlink_dump_tuples(struct sk_buff *skb,

		      const struct nf_conntrack_tuple *tuple)

{

	int ret;

	struct nf_conntrack_l3proto *l3proto;

	struct nf_conntrack_protocol *proto;



	l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);

	ret = ctnetlink_dump_tuples_ip(skb, tuple, l3proto);

	nf_ct_l3proto_put(l3proto);



	if (unlikely(ret < 0))

		return ret;



	nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);

	ret = ctnetlink_dump_tuples_proto(skb, tuple);

	NFA_NEST_END(skb, nest_parms);

	proto = nf_ct_proto_find_get(tuple->src.l3num, tuple->dst.protonum);

	ret = ctnetlink_dump_tuples_proto(skb, tuple, proto);

	nf_ct_proto_put(proto);



	return ret;



nfattr_failure:

	return -1;

}



static inline int
@@ -1152,6 +1161,37 @@ ctnetlink_exp_dump_tuple(struct sk_buff *skb, 
	return -1;

}			



static inline int

ctnetlink_exp_dump_mask(struct sk_buff *skb,

			const struct nf_conntrack_tuple *tuple,

			const struct nf_conntrack_tuple *mask)

{

	int ret;

	struct nf_conntrack_l3proto *l3proto;

	struct nf_conntrack_protocol *proto;

	struct nfattr *nest_parms = NFA_NEST(skb, CTA_EXPECT_MASK);



	l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);

	ret = ctnetlink_dump_tuples_ip(skb, mask, l3proto);

	nf_ct_l3proto_put(l3proto);



	if (unlikely(ret < 0))

		goto nfattr_failure;



	proto = nf_ct_proto_find_get(tuple->src.l3num, tuple->dst.protonum);

	ret = ctnetlink_dump_tuples_proto(skb, mask, proto);

	nf_ct_proto_put(proto);

	if (unlikely(ret < 0))

		goto nfattr_failure;



	NFA_NEST_END(skb, nest_parms);



	return 0;



nfattr_failure:

	return -1;

}



static inline int

ctnetlink_exp_dump_expect(struct sk_buff *skb,

                          const struct nf_conntrack_expect *exp)
@@ -1162,7 +1202,7 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb, 


	if (ctnetlink_exp_dump_tuple(skb, &exp->tuple, CTA_EXPECT_TUPLE) < 0)

		goto nfattr_failure;

	if (ctnetlink_exp_dump_tuple(skb, &exp->mask, CTA_EXPECT_MASK) < 0)

	if (ctnetlink_exp_dump_mask(skb, &exp->tuple, &exp->mask) < 0)

		goto nfattr_failure;

	if (ctnetlink_exp_dump_tuple(skb,

				 &master->tuplehash[IP_CT_DIR_ORIGINAL].tuple,