f6ac858589
Anonymous sets that are bound to rules from the same transaction trigger
a kernel splat from the abort path due to double set list removal and
double free.
This patch updates the logic to search for the transaction that is
responsible for creating the set and disable the set list removal and
release, given the rule is now responsible for this. Lookup is reverse
since the transaction that adds the set is likely to be at the tail of
the list.
Moreover, this patch adds the unbind step to deliver the event from the
commit path. This should not be done from the worker thread, since we
have no guarantees of in-order delivery to the listener.
This patch removes the assumption that both activate and deactivate
callbacks need to be provided.
Fixes: cd5125d8f5 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase")
Reported-by: Mikhail Morfikov <mmorfikov@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
239 lines
6 KiB
C
239 lines
6 KiB
C
/*
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* Copyright (c) 2012-2016 Pablo Neira Ayuso <pablo@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables.h>
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#define nft_objref_priv(expr) *((struct nft_object **)nft_expr_priv(expr))
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static void nft_objref_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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struct nft_object *obj = nft_objref_priv(expr);
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obj->ops->eval(obj, regs, pkt);
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}
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static int nft_objref_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_object *obj = nft_objref_priv(expr);
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u8 genmask = nft_genmask_next(ctx->net);
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u32 objtype;
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if (!tb[NFTA_OBJREF_IMM_NAME] ||
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!tb[NFTA_OBJREF_IMM_TYPE])
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return -EINVAL;
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objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE]));
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obj = nft_obj_lookup(ctx->table, tb[NFTA_OBJREF_IMM_NAME], objtype,
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genmask);
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if (IS_ERR(obj))
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return -ENOENT;
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nft_objref_priv(expr) = obj;
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obj->use++;
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return 0;
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}
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static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_object *obj = nft_objref_priv(expr);
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if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->name) ||
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nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE,
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htonl(obj->ops->type->type)))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static void nft_objref_destroy(const struct nft_ctx *ctx,
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const struct nft_expr *expr)
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{
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struct nft_object *obj = nft_objref_priv(expr);
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obj->use--;
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}
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static struct nft_expr_type nft_objref_type;
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static const struct nft_expr_ops nft_objref_ops = {
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.type = &nft_objref_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_object *)),
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.eval = nft_objref_eval,
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.init = nft_objref_init,
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.destroy = nft_objref_destroy,
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.dump = nft_objref_dump,
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};
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struct nft_objref_map {
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struct nft_set *set;
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enum nft_registers sreg:8;
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struct nft_set_binding binding;
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};
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static void nft_objref_map_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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struct nft_objref_map *priv = nft_expr_priv(expr);
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const struct nft_set *set = priv->set;
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const struct nft_set_ext *ext;
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struct nft_object *obj;
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bool found;
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found = set->ops->lookup(nft_net(pkt), set, ®s->data[priv->sreg],
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&ext);
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if (!found) {
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regs->verdict.code = NFT_BREAK;
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return;
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}
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obj = *nft_set_ext_obj(ext);
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obj->ops->eval(obj, regs, pkt);
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}
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static int nft_objref_map_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_objref_map *priv = nft_expr_priv(expr);
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u8 genmask = nft_genmask_next(ctx->net);
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struct nft_set *set;
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int err;
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set = nft_set_lookup_global(ctx->net, ctx->table,
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tb[NFTA_OBJREF_SET_NAME],
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tb[NFTA_OBJREF_SET_ID], genmask);
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if (IS_ERR(set))
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return PTR_ERR(set);
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if (!(set->flags & NFT_SET_OBJECT))
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return -EINVAL;
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priv->sreg = nft_parse_register(tb[NFTA_OBJREF_SET_SREG]);
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err = nft_validate_register_load(priv->sreg, set->klen);
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if (err < 0)
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return err;
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priv->binding.flags = set->flags & NFT_SET_OBJECT;
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err = nf_tables_bind_set(ctx, set, &priv->binding);
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if (err < 0)
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return err;
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priv->set = set;
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return 0;
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}
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static int nft_objref_map_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_objref_map *priv = nft_expr_priv(expr);
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if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) ||
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nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static void nft_objref_map_deactivate(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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enum nft_trans_phase phase)
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{
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struct nft_objref_map *priv = nft_expr_priv(expr);
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if (phase == NFT_TRANS_PREPARE)
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return;
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nf_tables_unbind_set(ctx, priv->set, &priv->binding,
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phase == NFT_TRANS_COMMIT);
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}
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static void nft_objref_map_destroy(const struct nft_ctx *ctx,
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const struct nft_expr *expr)
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{
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struct nft_objref_map *priv = nft_expr_priv(expr);
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nf_tables_destroy_set(ctx, priv->set);
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}
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static struct nft_expr_type nft_objref_type;
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static const struct nft_expr_ops nft_objref_map_ops = {
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.type = &nft_objref_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)),
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.eval = nft_objref_map_eval,
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.init = nft_objref_map_init,
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.deactivate = nft_objref_map_deactivate,
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.destroy = nft_objref_map_destroy,
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.dump = nft_objref_map_dump,
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};
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static const struct nft_expr_ops *
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nft_objref_select_ops(const struct nft_ctx *ctx,
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const struct nlattr * const tb[])
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{
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if (tb[NFTA_OBJREF_SET_SREG] &&
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(tb[NFTA_OBJREF_SET_NAME] ||
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tb[NFTA_OBJREF_SET_ID]))
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return &nft_objref_map_ops;
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else if (tb[NFTA_OBJREF_IMM_NAME] &&
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tb[NFTA_OBJREF_IMM_TYPE])
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return &nft_objref_ops;
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return ERR_PTR(-EOPNOTSUPP);
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}
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static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = {
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[NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING,
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.len = NFT_OBJ_MAXNAMELEN - 1 },
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[NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 },
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[NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 },
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[NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING,
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.len = NFT_SET_MAXNAMELEN - 1 },
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[NFTA_OBJREF_SET_ID] = { .type = NLA_U32 },
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};
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static struct nft_expr_type nft_objref_type __read_mostly = {
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.name = "objref",
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.select_ops = nft_objref_select_ops,
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.policy = nft_objref_policy,
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.maxattr = NFTA_OBJREF_MAX,
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.owner = THIS_MODULE,
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};
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static int __init nft_objref_module_init(void)
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{
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return nft_register_expr(&nft_objref_type);
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}
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static void __exit nft_objref_module_exit(void)
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{
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nft_unregister_expr(&nft_objref_type);
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}
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module_init(nft_objref_module_init);
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module_exit(nft_objref_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
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MODULE_ALIAS_NFT_EXPR("objref");
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