Commit 90fd131a authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
Browse files

netfilter: nf_tables: move dumper state allocation into ->start 



Shaochun Chen points out we leak dumper filter state allocations
stored in dump_control->data in case there is an error before netlink sets
cb_running (after which ->done will be called at some point).

In order to fix this, add .start functions and do the allocations
there.

->done is going to clean up, and in case error occurs before
->start invocation no cleanups need to be done anymore.

Reported-by: default avatarshaochun chen <cscnull@gmail.com>
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 6613b617

net/netfilter/nf_tables_api.c

+115 −104
Original line number Diff line number Diff line
@@ -2271,6 +2271,39 @@ done: 
	return skb->len;

}



static int nf_tables_dump_rules_start(struct netlink_callback *cb)

{

	const struct nlattr * const *nla = cb->data;

	struct nft_rule_dump_ctx *ctx = NULL;



	if (nla[NFTA_RULE_TABLE] || nla[NFTA_RULE_CHAIN]) {

		ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);

		if (!ctx)

			return -ENOMEM;



		if (nla[NFTA_RULE_TABLE]) {

			ctx->table = nla_strdup(nla[NFTA_RULE_TABLE],

							GFP_ATOMIC);

			if (!ctx->table) {

				kfree(ctx);

				return -ENOMEM;

			}

		}

		if (nla[NFTA_RULE_CHAIN]) {

			ctx->chain = nla_strdup(nla[NFTA_RULE_CHAIN],

						GFP_ATOMIC);

			if (!ctx->chain) {

				kfree(ctx->table);

				kfree(ctx);

				return -ENOMEM;

			}

		}

	}



	cb->data = ctx;

	return 0;

}



static int nf_tables_dump_rules_done(struct netlink_callback *cb)

{

	struct nft_rule_dump_ctx *ctx = cb->data;
@@ -2300,38 +2333,13 @@ static int nf_tables_getrule(struct net *net, struct sock *nlsk, 


	if (nlh->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.start= nf_tables_dump_rules_start,

			.dump = nf_tables_dump_rules,

			.done = nf_tables_dump_rules_done,

			.module = THIS_MODULE,

			.data = (void *)nla,

		};



		if (nla[NFTA_RULE_TABLE] || nla[NFTA_RULE_CHAIN]) {

			struct nft_rule_dump_ctx *ctx;



			ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);

			if (!ctx)

				return -ENOMEM;



			if (nla[NFTA_RULE_TABLE]) {

				ctx->table = nla_strdup(nla[NFTA_RULE_TABLE],

							GFP_ATOMIC);

				if (!ctx->table) {

					kfree(ctx);

					return -ENOMEM;

				}

			}

			if (nla[NFTA_RULE_CHAIN]) {

				ctx->chain = nla_strdup(nla[NFTA_RULE_CHAIN],

							GFP_ATOMIC);

				if (!ctx->chain) {

					kfree(ctx->table);

					kfree(ctx);

					return -ENOMEM;

				}

			}

			c.data = ctx;

		}



		return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);

	}
@@ -3181,6 +3189,18 @@ done: 
	return skb->len;

}



static int nf_tables_dump_sets_start(struct netlink_callback *cb)

{

	struct nft_ctx *ctx_dump = NULL;



	ctx_dump = kmemdup(cb->data, sizeof(*ctx_dump), GFP_ATOMIC);

	if (ctx_dump == NULL)

		return -ENOMEM;



	cb->data = ctx_dump;

	return 0;

}



static int nf_tables_dump_sets_done(struct netlink_callback *cb)

{

	kfree(cb->data);
@@ -3208,18 +3228,12 @@ static int nf_tables_getset(struct net *net, struct sock *nlsk, 


	if (nlh->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.start = nf_tables_dump_sets_start,

			.dump = nf_tables_dump_sets,

			.done = nf_tables_dump_sets_done,

			.data = &ctx,

			.module = THIS_MODULE,

		};

		struct nft_ctx *ctx_dump;



		ctx_dump = kmalloc(sizeof(*ctx_dump), GFP_ATOMIC);

		if (ctx_dump == NULL)

			return -ENOMEM;



		*ctx_dump = ctx;

		c.data = ctx_dump;



		return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);

	}
@@ -3869,6 +3883,15 @@ nla_put_failure: 
	return -ENOSPC;

}



static int nf_tables_dump_set_start(struct netlink_callback *cb)

{

	struct nft_set_dump_ctx *dump_ctx = cb->data;



	cb->data = kmemdup(dump_ctx, sizeof(*dump_ctx), GFP_ATOMIC);



	return cb->data ? 0 : -ENOMEM;

}



static int nf_tables_dump_set_done(struct netlink_callback *cb)

{

	kfree(cb->data);
@@ -4022,20 +4045,17 @@ static int nf_tables_getsetelem(struct net *net, struct sock *nlsk, 


	if (nlh->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.start = nf_tables_dump_set_start,

			.dump = nf_tables_dump_set,

			.done = nf_tables_dump_set_done,

			.module = THIS_MODULE,

		};

		struct nft_set_dump_ctx *dump_ctx;



		dump_ctx = kmalloc(sizeof(*dump_ctx), GFP_ATOMIC);

		if (!dump_ctx)

			return -ENOMEM;



		dump_ctx->set = set;

		dump_ctx->ctx = ctx;

		struct nft_set_dump_ctx dump_ctx = {

			.set = set,

			.ctx = ctx,

		};



		c.data = dump_ctx;

		c.data = &dump_ctx;

		return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);

	}
@@ -4995,38 +5015,42 @@ done: 
	return skb->len;

}



static int nf_tables_dump_obj_done(struct netlink_callback *cb)

{

	struct nft_obj_filter *filter = cb->data;



	if (filter) {

		kfree(filter->table);

		kfree(filter);

	}



	return 0;

}



static struct nft_obj_filter *

nft_obj_filter_alloc(const struct nlattr * const nla[])

static int nf_tables_dump_obj_start(struct netlink_callback *cb)

{

	struct nft_obj_filter *filter;

	const struct nlattr * const *nla = cb->data;

	struct nft_obj_filter *filter = NULL;



	if (nla[NFTA_OBJ_TABLE] || nla[NFTA_OBJ_TYPE]) {

		filter = kzalloc(sizeof(*filter), GFP_ATOMIC);

		if (!filter)

		return ERR_PTR(-ENOMEM);

			return -ENOMEM;



		if (nla[NFTA_OBJ_TABLE]) {

			filter->table = nla_strdup(nla[NFTA_OBJ_TABLE], GFP_ATOMIC);

			if (!filter->table) {

				kfree(filter);

			return ERR_PTR(-ENOMEM);

				return -ENOMEM;

			}

		}



		if (nla[NFTA_OBJ_TYPE])

			filter->type = ntohl(nla_get_be32(nla[NFTA_OBJ_TYPE]));

	}



	cb->data = filter;

	return 0;

}



static int nf_tables_dump_obj_done(struct netlink_callback *cb)

{

	struct nft_obj_filter *filter = cb->data;



	return filter;

	if (filter) {

		kfree(filter->table);

		kfree(filter);

	}



	return 0;

}



/* called with rcu_read_lock held */
@@ -5047,21 +5071,13 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk, 


	if (nlh->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.start = nf_tables_dump_obj_start,

			.dump = nf_tables_dump_obj,

			.done = nf_tables_dump_obj_done,

			.module = THIS_MODULE,

			.data = (void *)nla,

		};



		if (nla[NFTA_OBJ_TABLE] ||

		    nla[NFTA_OBJ_TYPE]) {

			struct nft_obj_filter *filter;



			filter = nft_obj_filter_alloc(nla);

			if (IS_ERR(filter))

				return -ENOMEM;



			c.data = filter;

		}

		return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);

	}
@@ -5667,37 +5683,39 @@ done: 
	return skb->len;

}



static int nf_tables_dump_flowtable_done(struct netlink_callback *cb)

static int nf_tables_dump_flowtable_start(struct netlink_callback *cb)

{

	struct nft_flowtable_filter *filter = cb->data;

	const struct nlattr * const *nla = cb->data;

	struct nft_flowtable_filter *filter = NULL;



	if (nla[NFTA_FLOWTABLE_TABLE]) {

		filter = kzalloc(sizeof(*filter), GFP_ATOMIC);

		if (!filter)

		return 0;

			return -ENOMEM;



	kfree(filter->table);

		filter->table = nla_strdup(nla[NFTA_FLOWTABLE_TABLE],

					   GFP_ATOMIC);

		if (!filter->table) {

			kfree(filter);

			return -ENOMEM;

		}

	}



	cb->data = filter;

	return 0;

}



static struct nft_flowtable_filter *

nft_flowtable_filter_alloc(const struct nlattr * const nla[])

static int nf_tables_dump_flowtable_done(struct netlink_callback *cb)

{

	struct nft_flowtable_filter *filter;

	struct nft_flowtable_filter *filter = cb->data;



	filter = kzalloc(sizeof(*filter), GFP_ATOMIC);

	if (!filter)

		return ERR_PTR(-ENOMEM);

		return 0;



	if (nla[NFTA_FLOWTABLE_TABLE]) {

		filter->table = nla_strdup(nla[NFTA_FLOWTABLE_TABLE],

					   GFP_ATOMIC);

		if (!filter->table) {

	kfree(filter->table);

	kfree(filter);

			return ERR_PTR(-ENOMEM);

		}

	}

	return filter;



	return 0;

}



/* called with rcu_read_lock held */
@@ -5717,20 +5735,13 @@ static int nf_tables_getflowtable(struct net *net, struct sock *nlsk, 


	if (nlh->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.start = nf_tables_dump_flowtable_start,

			.dump = nf_tables_dump_flowtable,

			.done = nf_tables_dump_flowtable_done,

			.module = THIS_MODULE,

			.data = (void *)nla,

		};



		if (nla[NFTA_FLOWTABLE_TABLE]) {

			struct nft_flowtable_filter *filter;



			filter = nft_flowtable_filter_alloc(nla);

			if (IS_ERR(filter))

				return -ENOMEM;



			c.data = filter;

		}

		return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);

	}

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