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Commit f6677f43 authored by Dmitry Mishin's avatar Dmitry Mishin Committed by David S. Miller
Browse files

[NETFILTER]: Fix iptables compat hook validation 



In compat mode, matches and targets valid hooks checks always successful due
to not initialized e->comefrom field yet. This patch separates this checks from
translation code and moves them after mark_source_chains() call, where these
marks are initialized.

Signed-off-by: default avatarDmitry Mishin <dim@openvz.org>
Signed-off-by; Patrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 74c9c0c1

net/ipv4/netfilter/ip_tables.c

+51 −27
Original line number Diff line number Diff line
@@ -1516,25 +1516,8 @@ static inline int compat_copy_match_from_user(struct ipt_entry_match *m, 
	void **dstptr, compat_uint_t *size, const char *name,

	const struct ipt_ip *ip, unsigned int hookmask)

{

	struct ipt_entry_match *dm;

	struct ipt_match *match;

	int ret;



	dm = (struct ipt_entry_match *)*dstptr;

	match = m->u.kernel.match;

	xt_compat_match_from_user(m, dstptr, size);



	ret = xt_check_match(match, AF_INET, dm->u.match_size - sizeof(*dm),

			     name, hookmask, ip->proto,

			     ip->invflags & IPT_INV_PROTO);

	if (!ret && m->u.kernel.match->checkentry

	    && !m->u.kernel.match->checkentry(name, ip, match, dm->data,

					      hookmask)) {

		duprintf("ip_tables: check failed for `%s'.\n",

			 m->u.kernel.match->name);

		ret = -EINVAL;

	}

	return ret;

	return 0;

}



static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
@@ -1556,7 +1539,7 @@ static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr, 
	ret = IPT_MATCH_ITERATE(e, compat_copy_match_from_user, dstptr, size,

			name, &de->ip, de->comefrom);

	if (ret)

		goto err;

		return ret;

	de->target_offset = e->target_offset - (origsize - *size);

	t = ipt_get_target(e);

	target = t->u.kernel.target;
@@ -1569,26 +1552,62 @@ static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr, 
		if ((unsigned char *)de - base < newinfo->underflow[h])

			newinfo->underflow[h] -= origsize - *size;

	}

	return ret;

}



static inline int compat_check_match(struct ipt_entry_match *m, const char *name,

				const struct ipt_ip *ip, unsigned int hookmask)

{

	struct ipt_match *match;

	int ret;



	match = m->u.kernel.match;

	ret = xt_check_match(match, AF_INET, m->u.match_size - sizeof(*m),

			     name, hookmask, ip->proto,

			     ip->invflags & IPT_INV_PROTO);

	if (!ret && m->u.kernel.match->checkentry

	    && !m->u.kernel.match->checkentry(name, ip, match, m->data,

					      hookmask)) {

		duprintf("ip_tables: compat: check failed for `%s'.\n",

			 m->u.kernel.match->name);

		ret = -EINVAL;

	}

	return ret;

}



	t = ipt_get_target(de);

static inline int compat_check_target(struct ipt_entry *e, const char *name)

{

 	struct ipt_entry_target *t;

 	struct ipt_target *target;

 	int ret;



	t = ipt_get_target(e);

	target = t->u.kernel.target;

	ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),

			      name, e->comefrom, e->ip.proto,

			      e->ip.invflags & IPT_INV_PROTO);

	if (ret)

		goto err;



	if (t->u.kernel.target->checkentry

		   && !t->u.kernel.target->checkentry(name, de, target,

						      t->data, de->comefrom)) {

	if (!ret && t->u.kernel.target->checkentry

		   && !t->u.kernel.target->checkentry(name, e, target,

						      t->data, e->comefrom)) {

		duprintf("ip_tables: compat: check failed for `%s'.\n",

			 t->u.kernel.target->name);

		ret = -EINVAL;

	}

err:

	return ret;

}



static inline int compat_check_entry(struct ipt_entry *e, const char *name)

{

	int ret;



	ret = IPT_MATCH_ITERATE(e, compat_check_match, name, &e->ip,

								e->comefrom);

	if (ret)

		return ret;



	return compat_check_target(e, name);

}



static int

translate_compat_table(const char *name,

		unsigned int valid_hooks,
@@ -1677,6 +1696,11 @@ translate_compat_table(const char *name, 
	if (!mark_source_chains(newinfo, valid_hooks, entry1))

		goto free_newinfo;



	ret = IPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,

									name);

	if (ret)

		goto free_newinfo;



	/* And one copy for every other CPU */

	for_each_possible_cpu(i)

		if (newinfo->entries[i] && newinfo->entries[i] != entry1)