From 1689f25924ada8fe14a4a82c38925d04994c7142 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 28 Jun 2023 16:24:27 +0200 Subject: netfilter: nf_tables: report use refcount overflow Overflow use refcount checks are not complete. Add helper function to deal with object reference counter tracking. Report -EMFILE in case UINT_MAX is reached. nft_use_dec() splats in case that reference counter underflows, which should not ever happen. Add nft_use_inc_restore() and nft_use_dec_restore() which are used to restore reference counter from error and abort paths. Use u32 in nft_flowtable and nft_object since helper functions cannot work on bitfields. Remove the few early incomplete checks now that the helper functions are in place and used to check for refcount overflow. Fixes: 96518518cc41 ("netfilter: add nftables") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 163 ++++++++++++++++++++++++--------------- net/netfilter/nft_flow_offload.c | 6 +- net/netfilter/nft_immediate.c | 8 +- net/netfilter/nft_objref.c | 8 +- 4 files changed, 114 insertions(+), 71 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 9573a8fcad79..86b3c4de7f40 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -253,8 +253,10 @@ int nf_tables_bind_chain(const struct nft_ctx *ctx, struct nft_chain *chain) if (chain->bound) return -EBUSY; + if (!nft_use_inc(&chain->use)) + return -EMFILE; + chain->bound = true; - chain->use++; nft_chain_trans_bind(ctx, chain); return 0; @@ -437,7 +439,7 @@ static int nft_delchain(struct nft_ctx *ctx) if (IS_ERR(trans)) return PTR_ERR(trans); - ctx->table->use--; + nft_use_dec(&ctx->table->use); nft_deactivate_next(ctx->net, ctx->chain); return 0; @@ -476,7 +478,7 @@ nf_tables_delrule_deactivate(struct nft_ctx *ctx, struct nft_rule *rule) /* You cannot delete the same rule twice */ if (nft_is_active_next(ctx->net, rule)) { nft_deactivate_next(ctx->net, rule); - ctx->chain->use--; + nft_use_dec(&ctx->chain->use); return 0; } return -ENOENT; @@ -644,7 +646,7 @@ static int nft_delset(const struct nft_ctx *ctx, struct nft_set *set) nft_map_deactivate(ctx, set); nft_deactivate_next(ctx->net, set); - ctx->table->use--; + nft_use_dec(&ctx->table->use); return err; } @@ -676,7 +678,7 @@ static int nft_delobj(struct nft_ctx *ctx, struct nft_object *obj) return err; nft_deactivate_next(ctx->net, obj); - ctx->table->use--; + nft_use_dec(&ctx->table->use); return err; } @@ -711,7 +713,7 @@ static int nft_delflowtable(struct nft_ctx *ctx, return err; nft_deactivate_next(ctx->net, flowtable); - ctx->table->use--; + nft_use_dec(&ctx->table->use); return err; } @@ -2396,9 +2398,6 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, struct nft_chain *chain; int err; - if (table->use == UINT_MAX) - return -EOVERFLOW; - if (nla[NFTA_CHAIN_HOOK]) { struct nft_stats __percpu *stats = NULL; struct nft_chain_hook hook = {}; @@ -2494,6 +2493,11 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, if (err < 0) goto err_destroy_chain; + if (!nft_use_inc(&table->use)) { + err = -EMFILE; + goto err_use; + } + trans = nft_trans_chain_add(ctx, NFT_MSG_NEWCHAIN); if (IS_ERR(trans)) { err = PTR_ERR(trans); @@ -2510,10 +2514,11 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask, goto err_unregister_hook; } - table->use++; - return 0; + err_unregister_hook: + nft_use_dec_restore(&table->use); +err_use: nf_tables_unregister_hook(net, table, chain); err_destroy_chain: nf_tables_chain_destroy(ctx); @@ -3840,9 +3845,6 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, return -EINVAL; handle = nf_tables_alloc_handle(table); - if (chain->use == UINT_MAX) - return -EOVERFLOW; - if (nla[NFTA_RULE_POSITION]) { pos_handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_POSITION])); old_rule = __nft_rule_lookup(chain, pos_handle); @@ -3936,6 +3938,11 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, } } + if (!nft_use_inc(&chain->use)) { + err = -EMFILE; + goto err_release_rule; + } + if (info->nlh->nlmsg_flags & NLM_F_REPLACE) { err = nft_delrule(&ctx, old_rule); if (err < 0) @@ -3967,7 +3974,6 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, } } kvfree(expr_info); - chain->use++; if (flow) nft_trans_flow_rule(trans) = flow; @@ -3978,6 +3984,7 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, return 0; err_destroy_flow_rule: + nft_use_dec_restore(&chain->use); if (flow) nft_flow_rule_destroy(flow); err_release_rule: @@ -5014,9 +5021,15 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, alloc_size = sizeof(*set) + size + udlen; if (alloc_size < size || alloc_size > INT_MAX) return -ENOMEM; + + if (!nft_use_inc(&table->use)) + return -EMFILE; + set = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT); - if (!set) - return -ENOMEM; + if (!set) { + err = -ENOMEM; + goto err_alloc; + } name = nla_strdup(nla[NFTA_SET_NAME], GFP_KERNEL_ACCOUNT); if (!name) { @@ -5074,7 +5087,7 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, goto err_set_expr_alloc; list_add_tail_rcu(&set->list, &table->sets); - table->use++; + return 0; err_set_expr_alloc: @@ -5086,6 +5099,9 @@ err_set_init: kfree(set->name); err_set_name: kvfree(set); +err_alloc: + nft_use_dec_restore(&table->use); + return err; } @@ -5224,9 +5240,6 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set, struct nft_set_binding *i; struct nft_set_iter iter; - if (set->use == UINT_MAX) - return -EOVERFLOW; - if (!list_empty(&set->bindings) && nft_set_is_anonymous(set)) return -EBUSY; @@ -5254,10 +5267,12 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set, return iter.err; } bind: + if (!nft_use_inc(&set->use)) + return -EMFILE; + binding->chain = ctx->chain; list_add_tail_rcu(&binding->list, &set->bindings); nft_set_trans_bind(ctx, set); - set->use++; return 0; } @@ -5331,7 +5346,7 @@ void nf_tables_activate_set(const struct nft_ctx *ctx, struct nft_set *set) nft_clear(ctx->net, set); } - set->use++; + nft_use_inc_restore(&set->use); } EXPORT_SYMBOL_GPL(nf_tables_activate_set); @@ -5347,7 +5362,7 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set, else list_del_rcu(&binding->list); - set->use--; + nft_use_dec(&set->use); break; case NFT_TRANS_PREPARE: if (nft_set_is_anonymous(set)) { @@ -5356,7 +5371,7 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set, nft_deactivate_next(ctx->net, set); } - set->use--; + nft_use_dec(&set->use); return; case NFT_TRANS_ABORT: case NFT_TRANS_RELEASE: @@ -5364,7 +5379,7 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set, set->flags & (NFT_SET_MAP | NFT_SET_OBJECT)) nft_map_deactivate(ctx, set); - set->use--; + nft_use_dec(&set->use); fallthrough; default: nf_tables_unbind_set(ctx, set, binding, @@ -6155,7 +6170,7 @@ void nft_set_elem_destroy(const struct nft_set *set, void *elem, nft_set_elem_expr_destroy(&ctx, nft_set_ext_expr(ext)); if (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF)) - (*nft_set_ext_obj(ext))->use--; + nft_use_dec(&(*nft_set_ext_obj(ext))->use); kfree(elem); } EXPORT_SYMBOL_GPL(nft_set_elem_destroy); @@ -6657,8 +6672,16 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, set->objtype, genmask); if (IS_ERR(obj)) { err = PTR_ERR(obj); + obj = NULL; goto err_parse_key_end; } + + if (!nft_use_inc(&obj->use)) { + err = -EMFILE; + obj = NULL; + goto err_parse_key_end; + } + err = nft_set_ext_add(&tmpl, NFT_SET_EXT_OBJREF); if (err < 0) goto err_parse_key_end; @@ -6727,10 +6750,9 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, if (flags) *nft_set_ext_flags(ext) = flags; - if (obj) { + if (obj) *nft_set_ext_obj(ext) = obj; - obj->use++; - } + if (ulen > 0) { if (nft_set_ext_check(&tmpl, NFT_SET_EXT_USERDATA, ulen) < 0) { err = -EINVAL; @@ -6798,12 +6820,13 @@ err_element_clash: kfree(trans); err_elem_free: nf_tables_set_elem_destroy(ctx, set, elem.priv); - if (obj) - obj->use--; err_parse_data: if (nla[NFTA_SET_ELEM_DATA] != NULL) nft_data_release(&elem.data.val, desc.type); err_parse_key_end: + if (obj) + nft_use_dec_restore(&obj->use); + nft_data_release(&elem.key_end.val, NFT_DATA_VALUE); err_parse_key: nft_data_release(&elem.key.val, NFT_DATA_VALUE); @@ -6883,7 +6906,7 @@ void nft_data_hold(const struct nft_data *data, enum nft_data_types type) case NFT_JUMP: case NFT_GOTO: chain = data->verdict.chain; - chain->use++; + nft_use_inc_restore(&chain->use); break; } } @@ -6898,7 +6921,7 @@ static void nft_setelem_data_activate(const struct net *net, if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA)) nft_data_hold(nft_set_ext_data(ext), set->dtype); if (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF)) - (*nft_set_ext_obj(ext))->use++; + nft_use_inc_restore(&(*nft_set_ext_obj(ext))->use); } static void nft_setelem_data_deactivate(const struct net *net, @@ -6910,7 +6933,7 @@ static void nft_setelem_data_deactivate(const struct net *net, if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA)) nft_data_release(nft_set_ext_data(ext), set->dtype); if (nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF)) - (*nft_set_ext_obj(ext))->use--; + nft_use_dec(&(*nft_set_ext_obj(ext))->use); } static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set, @@ -7453,9 +7476,14 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info, nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla); + if (!nft_use_inc(&table->use)) + return -EMFILE; + type = nft_obj_type_get(net, objtype); - if (IS_ERR(type)) - return PTR_ERR(type); + if (IS_ERR(type)) { + err = PTR_ERR(type); + goto err_type; + } obj = nft_obj_init(&ctx, type, nla[NFTA_OBJ_DATA]); if (IS_ERR(obj)) { @@ -7489,7 +7517,7 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info, goto err_obj_ht; list_add_tail_rcu(&obj->list, &table->objects); - table->use++; + return 0; err_obj_ht: /* queued in transaction log */ @@ -7505,6 +7533,9 @@ err_strdup: kfree(obj); err_init: module_put(type->owner); +err_type: + nft_use_dec_restore(&table->use); + return err; } @@ -7906,7 +7937,7 @@ void nf_tables_deactivate_flowtable(const struct nft_ctx *ctx, case NFT_TRANS_PREPARE: case NFT_TRANS_ABORT: case NFT_TRANS_RELEASE: - flowtable->use--; + nft_use_dec(&flowtable->use); fallthrough; default: return; @@ -8260,9 +8291,14 @@ static int nf_tables_newflowtable(struct sk_buff *skb, nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla); + if (!nft_use_inc(&table->use)) + return -EMFILE; + flowtable = kzalloc(sizeof(*flowtable), GFP_KERNEL_ACCOUNT); - if (!flowtable) - return -ENOMEM; + if (!flowtable) { + err = -ENOMEM; + goto flowtable_alloc; + } flowtable->table = table; flowtable->handle = nf_tables_alloc_handle(table); @@ -8317,7 +8353,6 @@ static int nf_tables_newflowtable(struct sk_buff *skb, goto err5; list_add_tail_rcu(&flowtable->list, &table->flowtables); - table->use++; return 0; err5: @@ -8334,6 +8369,9 @@ err2: kfree(flowtable->name); err1: kfree(flowtable); +flowtable_alloc: + nft_use_dec_restore(&table->use); + return err; } @@ -9713,7 +9751,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) */ if (nft_set_is_anonymous(nft_trans_set(trans)) && !list_empty(&nft_trans_set(trans)->bindings)) - trans->ctx.table->use--; + nft_use_dec(&trans->ctx.table->use); } nf_tables_set_notify(&trans->ctx, nft_trans_set(trans), NFT_MSG_NEWSET, GFP_KERNEL); @@ -9943,7 +9981,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) nft_trans_destroy(trans); break; } - trans->ctx.table->use--; + nft_use_dec_restore(&trans->ctx.table->use); nft_chain_del(trans->ctx.chain); nf_tables_unregister_hook(trans->ctx.net, trans->ctx.table, @@ -9956,7 +9994,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) list_splice(&nft_trans_chain_hooks(trans), &nft_trans_basechain(trans)->hook_list); } else { - trans->ctx.table->use++; + nft_use_inc_restore(&trans->ctx.table->use); nft_clear(trans->ctx.net, trans->ctx.chain); } nft_trans_destroy(trans); @@ -9966,7 +10004,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) nft_trans_destroy(trans); break; } - trans->ctx.chain->use--; + nft_use_dec_restore(&trans->ctx.chain->use); list_del_rcu(&nft_trans_rule(trans)->list); nft_rule_expr_deactivate(&trans->ctx, nft_trans_rule(trans), @@ -9976,7 +10014,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) break; case NFT_MSG_DELRULE: case NFT_MSG_DESTROYRULE: - trans->ctx.chain->use++; + nft_use_inc_restore(&trans->ctx.chain->use); nft_clear(trans->ctx.net, nft_trans_rule(trans)); nft_rule_expr_activate(&trans->ctx, nft_trans_rule(trans)); if (trans->ctx.chain->flags & NFT_CHAIN_HW_OFFLOAD) @@ -9989,7 +10027,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) nft_trans_destroy(trans); break; } - trans->ctx.table->use--; + nft_use_dec_restore(&trans->ctx.table->use); if (nft_trans_set_bound(trans)) { nft_trans_destroy(trans); break; @@ -9998,7 +10036,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) break; case NFT_MSG_DELSET: case NFT_MSG_DESTROYSET: - trans->ctx.table->use++; + nft_use_inc_restore(&trans->ctx.table->use); nft_clear(trans->ctx.net, nft_trans_set(trans)); if (nft_trans_set(trans)->flags & (NFT_SET_MAP | NFT_SET_OBJECT)) nft_map_activate(&trans->ctx, nft_trans_set(trans)); @@ -10042,13 +10080,13 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) nft_obj_destroy(&trans->ctx, nft_trans_obj_newobj(trans)); nft_trans_destroy(trans); } else { - trans->ctx.table->use--; + nft_use_dec_restore(&trans->ctx.table->use); nft_obj_del(nft_trans_obj(trans)); } break; case NFT_MSG_DELOBJ: case NFT_MSG_DESTROYOBJ: - trans->ctx.table->use++; + nft_use_inc_restore(&trans->ctx.table->use); nft_clear(trans->ctx.net, nft_trans_obj(trans)); nft_trans_destroy(trans); break; @@ -10057,7 +10095,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) nft_unregister_flowtable_net_hooks(net, &nft_trans_flowtable_hooks(trans)); } else { - trans->ctx.table->use--; + nft_use_dec_restore(&trans->ctx.table->use); list_del_rcu(&nft_trans_flowtable(trans)->list); nft_unregister_flowtable_net_hooks(net, &nft_trans_flowtable(trans)->hook_list); @@ -10069,7 +10107,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) list_splice(&nft_trans_flowtable_hooks(trans), &nft_trans_flowtable(trans)->hook_list); } else { - trans->ctx.table->use++; + nft_use_inc_restore(&trans->ctx.table->use); nft_clear(trans->ctx.net, nft_trans_flowtable(trans)); } nft_trans_destroy(trans); @@ -10518,8 +10556,9 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, if (desc->flags & NFT_DATA_DESC_SETELEM && chain->flags & NFT_CHAIN_BINDING) return -EINVAL; + if (!nft_use_inc(&chain->use)) + return -EMFILE; - chain->use++; data->verdict.chain = chain; break; } @@ -10537,7 +10576,7 @@ static void nft_verdict_uninit(const struct nft_data *data) case NFT_JUMP: case NFT_GOTO: chain = data->verdict.chain; - chain->use--; + nft_use_dec(&chain->use); break; } } @@ -10706,11 +10745,11 @@ int __nft_release_basechain(struct nft_ctx *ctx) nf_tables_unregister_hook(ctx->net, ctx->chain->table, ctx->chain); list_for_each_entry_safe(rule, nr, &ctx->chain->rules, list) { list_del(&rule->list); - ctx->chain->use--; + nft_use_dec(&ctx->chain->use); nf_tables_rule_release(ctx, rule); } nft_chain_del(ctx->chain); - ctx->table->use--; + nft_use_dec(&ctx->table->use); nf_tables_chain_destroy(ctx); return 0; @@ -10760,18 +10799,18 @@ static void __nft_release_table(struct net *net, struct nft_table *table) ctx.chain = chain; list_for_each_entry_safe(rule, nr, &chain->rules, list) { list_del(&rule->list); - chain->use--; + nft_use_dec(&chain->use); nf_tables_rule_release(&ctx, rule); } } list_for_each_entry_safe(flowtable, nf, &table->flowtables, list) { list_del(&flowtable->list); - table->use--; + nft_use_dec(&table->use); nf_tables_flowtable_destroy(flowtable); } list_for_each_entry_safe(set, ns, &table->sets, list) { list_del(&set->list); - table->use--; + nft_use_dec(&table->use); if (set->flags & (NFT_SET_MAP | NFT_SET_OBJECT)) nft_map_deactivate(&ctx, set); @@ -10779,13 +10818,13 @@ static void __nft_release_table(struct net *net, struct nft_table *table) } list_for_each_entry_safe(obj, ne, &table->objects, list) { nft_obj_del(obj); - table->use--; + nft_use_dec(&table->use); nft_obj_destroy(&ctx, obj); } list_for_each_entry_safe(chain, nc, &table->chains, list) { ctx.chain = chain; nft_chain_del(chain); - table->use--; + nft_use_dec(&table->use); nf_tables_chain_destroy(&ctx); } nf_tables_table_destroy(&ctx); diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c index 5ef9146e74ad..ab3362c483b4 100644 --- a/net/netfilter/nft_flow_offload.c +++ b/net/netfilter/nft_flow_offload.c @@ -408,8 +408,10 @@ static int nft_flow_offload_init(const struct nft_ctx *ctx, if (IS_ERR(flowtable)) return PTR_ERR(flowtable); + if (!nft_use_inc(&flowtable->use)) + return -EMFILE; + priv->flowtable = flowtable; - flowtable->use++; return nf_ct_netns_get(ctx->net, ctx->family); } @@ -428,7 +430,7 @@ static void nft_flow_offload_activate(const struct nft_ctx *ctx, { struct nft_flow_offload *priv = nft_expr_priv(expr); - priv->flowtable->use++; + nft_use_inc_restore(&priv->flowtable->use); } static void nft_flow_offload_destroy(const struct nft_ctx *ctx, diff --git a/net/netfilter/nft_immediate.c b/net/netfilter/nft_immediate.c index 3d76ebfe8939..407d7197f75b 100644 --- a/net/netfilter/nft_immediate.c +++ b/net/netfilter/nft_immediate.c @@ -159,7 +159,7 @@ static void nft_immediate_deactivate(const struct nft_ctx *ctx, default: nft_chain_del(chain); chain->bound = false; - chain->table->use--; + nft_use_dec(&chain->table->use); break; } break; @@ -198,7 +198,7 @@ static void nft_immediate_destroy(const struct nft_ctx *ctx, * let the transaction records release this chain and its rules. */ if (chain->bound) { - chain->use--; + nft_use_dec(&chain->use); break; } @@ -206,9 +206,9 @@ static void nft_immediate_destroy(const struct nft_ctx *ctx, chain_ctx = *ctx; chain_ctx.chain = chain; - chain->use--; + nft_use_dec(&chain->use); list_for_each_entry_safe(rule, n, &chain->rules, list) { - chain->use--; + nft_use_dec(&chain->use); list_del(&rule->list); nf_tables_rule_destroy(&chain_ctx, rule); } diff --git a/net/netfilter/nft_objref.c b/net/netfilter/nft_objref.c index a48dd5b5d45b..509011b1ef59 100644 --- a/net/netfilter/nft_objref.c +++ b/net/netfilter/nft_objref.c @@ -41,8 +41,10 @@ static int nft_objref_init(const struct nft_ctx *ctx, if (IS_ERR(obj)) return -ENOENT; + if (!nft_use_inc(&obj->use)) + return -EMFILE; + nft_objref_priv(expr) = obj; - obj->use++; return 0; } @@ -72,7 +74,7 @@ static void nft_objref_deactivate(const struct nft_ctx *ctx, if (phase == NFT_TRANS_COMMIT) return; - obj->use--; + nft_use_dec(&obj->use); } static void nft_objref_activate(const struct nft_ctx *ctx, @@ -80,7 +82,7 @@ static void nft_objref_activate(const struct nft_ctx *ctx, { struct nft_object *obj = nft_objref_priv(expr); - obj->use++; + nft_use_inc_restore(&obj->use); } static const struct nft_expr_ops nft_objref_ops = { -- cgit v1.2.3 From 8a9dc07ba92497a81f1ff65d25c2ba7b6f9a8bdc Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 3 Jul 2023 13:43:18 +0200 Subject: netfilter: conntrack: gre: don't set assured flag for clash entries Now that conntrack core is allowd to insert clashing entries, make sure GRE won't set assured flag on NAT_CLASH entries, just like UDP. Doing so prevents early_drop logic for these entries. Fixes: d671fd82eaa9 ("netfilter: conntrack: allow insertion clash of gre protocol") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_proto_gre.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c index ad6f0ca40cd2..af369e686fc5 100644 --- a/net/netfilter/nf_conntrack_proto_gre.c +++ b/net/netfilter/nf_conntrack_proto_gre.c @@ -205,6 +205,8 @@ int nf_conntrack_gre_packet(struct nf_conn *ct, enum ip_conntrack_info ctinfo, const struct nf_hook_state *state) { + unsigned long status; + if (!nf_ct_is_confirmed(ct)) { unsigned int *timeouts = nf_ct_timeout_lookup(ct); @@ -217,11 +219,17 @@ int nf_conntrack_gre_packet(struct nf_conn *ct, ct->proto.gre.timeout = timeouts[GRE_CT_UNREPLIED]; } + status = READ_ONCE(ct->status); /* If we've seen traffic both ways, this is a GRE connection. * Extend timeout. */ - if (ct->status & IPS_SEEN_REPLY) { + if (status & IPS_SEEN_REPLY) { nf_ct_refresh_acct(ct, ctinfo, skb, ct->proto.gre.stream_timeout); + + /* never set ASSURED for IPS_NAT_CLASH, they time out soon */ + if (unlikely((status & IPS_NAT_CLASH))) + return NF_ACCEPT; + /* Also, more likely to be important, and not a probe. */ if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status)) nf_conntrack_event_cache(IPCT_ASSURED, ct); -- cgit v1.2.3 From 6eef7a2b933885a17679eb8ed0796ddf0ee5309b Mon Sep 17 00:00:00 2001 From: Florent Revest Date: Mon, 3 Jul 2023 16:52:16 +0200 Subject: netfilter: conntrack: Avoid nf_ct_helper_hash uses after free If nf_conntrack_init_start() fails (for example due to a register_nf_conntrack_bpf() failure), the nf_conntrack_helper_fini() clean-up path frees the nf_ct_helper_hash map. When built with NF_CONNTRACK=y, further netfilter modules (e.g: netfilter_conntrack_ftp) can still be loaded and call nf_conntrack_helpers_register(), independently of whether nf_conntrack initialized correctly. This accesses the nf_ct_helper_hash dangling pointer and causes a uaf, possibly leading to random memory corruption. This patch guards nf_conntrack_helper_register() from accessing a freed or uninitialized nf_ct_helper_hash pointer and fixes possible uses-after-free when loading a conntrack module. Cc: stable@vger.kernel.org Fixes: 12f7a505331e ("netfilter: add user-space connection tracking helper infrastructure") Signed-off-by: Florent Revest Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_helper.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index 0c4db2f2ac43..f22691f83853 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -360,6 +360,9 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me) BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES); BUG_ON(strlen(me->name) > NF_CT_HELPER_NAME_LEN - 1); + if (!nf_ct_helper_hash) + return -ENOENT; + if (me->expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT) return -EINVAL; @@ -515,4 +518,5 @@ int nf_conntrack_helper_init(void) void nf_conntrack_helper_fini(void) { kvfree(nf_ct_helper_hash); + nf_ct_helper_hash = NULL; } -- cgit v1.2.3 From eaf9e7192ec9af2fbf1b6eb2299dd0feca6c5f7e Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 4 Jul 2023 12:25:23 +0200 Subject: netfilter: conntrack: don't fold port numbers into addresses before hashing Originally this used jhash2() over tuple and folded the zone id, the pernet hash value, destination port and l4 protocol number into the 32bit seed value. When the switch to siphash was done, I used an on-stack temporary buffer to build a suitable key to be hashed via siphash(). But this showed up as performance regression, so I got rid of the temporary copy and collected to-be-hashed data in 4 u64 variables. This makes it easy to build tuples that produce the same hash, which isn't desirable even though chain lengths are limited. Switch back to plain siphash, but just like with jhash2(), take advantage of the fact that most of to-be-hashed data is already in a suitable order. Use an empty struct as annotation in 'struct nf_conntrack_tuple' to mark last member that can be used as hash input. The only remaining data that isn't present in the tuple structure are the zone identifier and the pernet hash: fold those into the key. Fixes: d2c806abcf0b ("netfilter: conntrack: use siphash_4u64") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_core.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index d119f1d4c2fc..992393102d5f 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -211,24 +211,18 @@ static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, unsigned int zoneid, const struct net *net) { - u64 a, b, c, d; + siphash_key_t key; get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd)); - /* The direction must be ignored, handle usable tuplehash members manually */ - a = (u64)tuple->src.u3.all[0] << 32 | tuple->src.u3.all[3]; - b = (u64)tuple->dst.u3.all[0] << 32 | tuple->dst.u3.all[3]; + key = nf_conntrack_hash_rnd; - c = (__force u64)tuple->src.u.all << 32 | (__force u64)tuple->dst.u.all << 16; - c |= tuple->dst.protonum; + key.key[0] ^= zoneid; + key.key[1] ^= net_hash_mix(net); - d = (u64)zoneid << 32 | net_hash_mix(net); - - /* IPv4: u3.all[1,2,3] == 0 */ - c ^= (u64)tuple->src.u3.all[1] << 32 | tuple->src.u3.all[2]; - d += (u64)tuple->dst.u3.all[1] << 32 | tuple->dst.u3.all[2]; - - return (u32)siphash_4u64(a, b, c, d, &nf_conntrack_hash_rnd); + return siphash((void *)tuple, + offsetofend(struct nf_conntrack_tuple, dst.__nfct_hash_offsetend), + &key); } static u32 scale_hash(u32 hash) -- cgit v1.2.3 From 515ad530795c118f012539ed76d02bacfd426d89 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Wed, 5 Jul 2023 09:12:55 -0300 Subject: netfilter: nf_tables: do not ignore genmask when looking up chain by id When adding a rule to a chain referring to its ID, if that chain had been deleted on the same batch, the rule might end up referring to a deleted chain. This will lead to a WARNING like following: [ 33.098431] ------------[ cut here ]------------ [ 33.098678] WARNING: CPU: 5 PID: 69 at net/netfilter/nf_tables_api.c:2037 nf_tables_chain_destroy+0x23d/0x260 [ 33.099217] Modules linked in: [ 33.099388] CPU: 5 PID: 69 Comm: kworker/5:1 Not tainted 6.4.0+ #409 [ 33.099726] Workqueue: events nf_tables_trans_destroy_work [ 33.100018] RIP: 0010:nf_tables_chain_destroy+0x23d/0x260 [ 33.100306] Code: 8b 7c 24 68 e8 64 9c ed fe 4c 89 e7 e8 5c 9c ed fe 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 89 c6 89 c7 c3 cc cc cc cc <0f> 0b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 89 c6 89 c7 [ 33.101271] RSP: 0018:ffffc900004ffc48 EFLAGS: 00010202 [ 33.101546] RAX: 0000000000000001 RBX: ffff888006fc0a28 RCX: 0000000000000000 [ 33.101920] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 33.102649] RBP: ffffc900004ffc78 R08: 0000000000000000 R09: 0000000000000000 [ 33.103018] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880135ef500 [ 33.103385] R13: 0000000000000000 R14: dead000000000122 R15: ffff888006fc0a10 [ 33.103762] FS: 0000000000000000(0000) GS:ffff888024c80000(0000) knlGS:0000000000000000 [ 33.104184] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 33.104493] CR2: 00007fe863b56a50 CR3: 00000000124b0001 CR4: 0000000000770ee0 [ 33.104872] PKRU: 55555554 [ 33.104999] Call Trace: [ 33.105113] [ 33.105214] ? show_regs+0x72/0x90 [ 33.105371] ? __warn+0xa5/0x210 [ 33.105520] ? nf_tables_chain_destroy+0x23d/0x260 [ 33.105732] ? report_bug+0x1f2/0x200 [ 33.105902] ? handle_bug+0x46/0x90 [ 33.106546] ? exc_invalid_op+0x19/0x50 [ 33.106762] ? asm_exc_invalid_op+0x1b/0x20 [ 33.106995] ? nf_tables_chain_destroy+0x23d/0x260 [ 33.107249] ? nf_tables_chain_destroy+0x30/0x260 [ 33.107506] nf_tables_trans_destroy_work+0x669/0x680 [ 33.107782] ? mark_held_locks+0x28/0xa0 [ 33.107996] ? __pfx_nf_tables_trans_destroy_work+0x10/0x10 [ 33.108294] ? _raw_spin_unlock_irq+0x28/0x70 [ 33.108538] process_one_work+0x68c/0xb70 [ 33.108755] ? lock_acquire+0x17f/0x420 [ 33.108977] ? __pfx_process_one_work+0x10/0x10 [ 33.109218] ? do_raw_spin_lock+0x128/0x1d0 [ 33.109435] ? _raw_spin_lock_irq+0x71/0x80 [ 33.109634] worker_thread+0x2bd/0x700 [ 33.109817] ? __pfx_worker_thread+0x10/0x10 [ 33.110254] kthread+0x18b/0x1d0 [ 33.110410] ? __pfx_kthread+0x10/0x10 [ 33.110581] ret_from_fork+0x29/0x50 [ 33.110757] [ 33.110866] irq event stamp: 1651 [ 33.111017] hardirqs last enabled at (1659): [] __up_console_sem+0x79/0xa0 [ 33.111379] hardirqs last disabled at (1666): [] __up_console_sem+0x5e/0xa0 [ 33.111740] softirqs last enabled at (1616): [] __irq_exit_rcu+0x9e/0xe0 [ 33.112094] softirqs last disabled at (1367): [] __irq_exit_rcu+0x9e/0xe0 [ 33.112453] ---[ end trace 0000000000000000 ]--- This is due to the nft_chain_lookup_byid ignoring the genmask. After this change, adding the new rule will fail as it will not find the chain. Fixes: 837830a4b439 ("netfilter: nf_tables: add NFTA_RULE_CHAIN_ID attribute") Cc: stable@vger.kernel.org Reported-by: Mingi Cho of Theori working with ZDI Signed-off-by: Thadeu Lima de Souza Cascardo Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 86b3c4de7f40..237f739da3ca 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2699,7 +2699,7 @@ err_hooks: static struct nft_chain *nft_chain_lookup_byid(const struct net *net, const struct nft_table *table, - const struct nlattr *nla) + const struct nlattr *nla, u8 genmask) { struct nftables_pernet *nft_net = nft_pernet(net); u32 id = ntohl(nla_get_be32(nla)); @@ -2710,7 +2710,8 @@ static struct nft_chain *nft_chain_lookup_byid(const struct net *net, if (trans->msg_type == NFT_MSG_NEWCHAIN && chain->table == table && - id == nft_trans_chain_id(trans)) + id == nft_trans_chain_id(trans) && + nft_active_genmask(chain, genmask)) return chain; } return ERR_PTR(-ENOENT); @@ -3814,7 +3815,8 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, return -EOPNOTSUPP; } else if (nla[NFTA_RULE_CHAIN_ID]) { - chain = nft_chain_lookup_byid(net, table, nla[NFTA_RULE_CHAIN_ID]); + chain = nft_chain_lookup_byid(net, table, nla[NFTA_RULE_CHAIN_ID], + genmask); if (IS_ERR(chain)) { NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_CHAIN_ID]); return PTR_ERR(chain); @@ -10540,7 +10542,8 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data, genmask); } else if (tb[NFTA_VERDICT_CHAIN_ID]) { chain = nft_chain_lookup_byid(ctx->net, ctx->table, - tb[NFTA_VERDICT_CHAIN_ID]); + tb[NFTA_VERDICT_CHAIN_ID], + genmask); if (IS_ERR(chain)) return PTR_ERR(chain); } else { -- cgit v1.2.3 From caf3ef7468f7534771b5c44cd8dbd6f7f87c2cbd Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Wed, 5 Jul 2023 18:05:35 -0300 Subject: netfilter: nf_tables: prevent OOB access in nft_byteorder_eval When evaluating byteorder expressions with size 2, a union with 32-bit and 16-bit members is used. Since the 16-bit members are aligned to 32-bit, the array accesses will be out-of-bounds. It may lead to a stack-out-of-bounds access like the one below: [ 23.095215] ================================================================== [ 23.095625] BUG: KASAN: stack-out-of-bounds in nft_byteorder_eval+0x13c/0x320 [ 23.096020] Read of size 2 at addr ffffc90000007948 by task ping/115 [ 23.096358] [ 23.096456] CPU: 0 PID: 115 Comm: ping Not tainted 6.4.0+ #413 [ 23.096770] Call Trace: [ 23.096910] [ 23.097030] dump_stack_lvl+0x60/0xc0 [ 23.097218] print_report+0xcf/0x630 [ 23.097388] ? nft_byteorder_eval+0x13c/0x320 [ 23.097577] ? kasan_addr_to_slab+0xd/0xc0 [ 23.097760] ? nft_byteorder_eval+0x13c/0x320 [ 23.097949] kasan_report+0xc9/0x110 [ 23.098106] ? nft_byteorder_eval+0x13c/0x320 [ 23.098298] __asan_load2+0x83/0xd0 [ 23.098453] nft_byteorder_eval+0x13c/0x320 [ 23.098659] nft_do_chain+0x1c8/0xc50 [ 23.098852] ? __pfx_nft_do_chain+0x10/0x10 [ 23.099078] ? __kasan_check_read+0x11/0x20 [ 23.099295] ? __pfx___lock_acquire+0x10/0x10 [ 23.099535] ? __pfx___lock_acquire+0x10/0x10 [ 23.099745] ? __kasan_check_read+0x11/0x20 [ 23.099929] nft_do_chain_ipv4+0xfe/0x140 [ 23.100105] ? __pfx_nft_do_chain_ipv4+0x10/0x10 [ 23.100327] ? lock_release+0x204/0x400 [ 23.100515] ? nf_hook.constprop.0+0x340/0x550 [ 23.100779] nf_hook_slow+0x6c/0x100 [ 23.100977] ? __pfx_nft_do_chain_ipv4+0x10/0x10 [ 23.101223] nf_hook.constprop.0+0x334/0x550 [ 23.101443] ? __pfx_ip_local_deliver_finish+0x10/0x10 [ 23.101677] ? __pfx_nf_hook.constprop.0+0x10/0x10 [ 23.101882] ? __pfx_ip_rcv_finish+0x10/0x10 [ 23.102071] ? __pfx_ip_local_deliver_finish+0x10/0x10 [ 23.102291] ? rcu_read_lock_held+0x4b/0x70 [ 23.102481] ip_local_deliver+0xbb/0x110 [ 23.102665] ? __pfx_ip_rcv+0x10/0x10 [ 23.102839] ip_rcv+0x199/0x2a0 [ 23.102980] ? __pfx_ip_rcv+0x10/0x10 [ 23.103140] __netif_receive_skb_one_core+0x13e/0x150 [ 23.103362] ? __pfx___netif_receive_skb_one_core+0x10/0x10 [ 23.103647] ? mark_held_locks+0x48/0xa0 [ 23.103819] ? process_backlog+0x36c/0x380 [ 23.103999] __netif_receive_skb+0x23/0xc0 [ 23.104179] process_backlog+0x91/0x380 [ 23.104350] __napi_poll.constprop.0+0x66/0x360 [ 23.104589] ? net_rx_action+0x1cb/0x610 [ 23.104811] net_rx_action+0x33e/0x610 [ 23.105024] ? _raw_spin_unlock+0x23/0x50 [ 23.105257] ? __pfx_net_rx_action+0x10/0x10 [ 23.105485] ? mark_held_locks+0x48/0xa0 [ 23.105741] __do_softirq+0xfa/0x5ab [ 23.105956] ? __dev_queue_xmit+0x765/0x1c00 [ 23.106193] do_softirq.part.0+0x49/0xc0 [ 23.106423] [ 23.106547] [ 23.106670] __local_bh_enable_ip+0xf5/0x120 [ 23.106903] __dev_queue_xmit+0x789/0x1c00 [ 23.107131] ? __pfx___dev_queue_xmit+0x10/0x10 [ 23.107381] ? find_held_lock+0x8e/0xb0 [ 23.107585] ? lock_release+0x204/0x400 [ 23.107798] ? neigh_resolve_output+0x185/0x350 [ 23.108049] ? mark_held_locks+0x48/0xa0 [ 23.108265] ? neigh_resolve_output+0x185/0x350 [ 23.108514] neigh_resolve_output+0x246/0x350 [ 23.108753] ? neigh_resolve_output+0x246/0x350 [ 23.109003] ip_finish_output2+0x3c3/0x10b0 [ 23.109250] ? __pfx_ip_finish_output2+0x10/0x10 [ 23.109510] ? __pfx_nf_hook+0x10/0x10 [ 23.109732] __ip_finish_output+0x217/0x390 [ 23.109978] ip_finish_output+0x2f/0x130 [ 23.110207] ip_output+0xc9/0x170 [ 23.110404] ip_push_pending_frames+0x1a0/0x240 [ 23.110652] raw_sendmsg+0x102e/0x19e0 [ 23.110871] ? __pfx_raw_sendmsg+0x10/0x10 [ 23.111093] ? lock_release+0x204/0x400 [ 23.111304] ? __mod_lruvec_page_state+0x148/0x330 [ 23.111567] ? find_held_lock+0x8e/0xb0 [ 23.111777] ? find_held_lock+0x8e/0xb0 [ 23.111993] ? __rcu_read_unlock+0x7c/0x2f0 [ 23.112225] ? aa_sk_perm+0x18a/0x550 [ 23.112431] ? filemap_map_pages+0x4f1/0x900 [ 23.112665] ? __pfx_aa_sk_perm+0x10/0x10 [ 23.112880] ? find_held_lock+0x8e/0xb0 [ 23.113098] inet_sendmsg+0xa0/0xb0 [ 23.113297] ? inet_sendmsg+0xa0/0xb0 [ 23.113500] ? __pfx_inet_sendmsg+0x10/0x10 [ 23.113727] sock_sendmsg+0xf4/0x100 [ 23.113924] ? move_addr_to_kernel.part.0+0x4f/0xa0 [ 23.114190] __sys_sendto+0x1d4/0x290 [ 23.114391] ? __pfx___sys_sendto+0x10/0x10 [ 23.114621] ? __pfx_mark_lock.part.0+0x10/0x10 [ 23.114869] ? lock_release+0x204/0x400 [ 23.115076] ? find_held_lock+0x8e/0xb0 [ 23.115287] ? rcu_is_watching+0x23/0x60 [ 23.115503] ? __rseq_handle_notify_resume+0x6e2/0x860 [ 23.115778] ? __kasan_check_write+0x14/0x30 [ 23.116008] ? blkcg_maybe_throttle_current+0x8d/0x770 [ 23.116285] ? mark_held_locks+0x28/0xa0 [ 23.116503] ? do_syscall_64+0x37/0x90 [ 23.116713] __x64_sys_sendto+0x7f/0xb0 [ 23.116924] do_syscall_64+0x59/0x90 [ 23.117123] ? irqentry_exit_to_user_mode+0x25/0x30 [ 23.117387] ? irqentry_exit+0x77/0xb0 [ 23.117593] ? exc_page_fault+0x92/0x140 [ 23.117806] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 23.118081] RIP: 0033:0x7f744aee2bba [ 23.118282] Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89 [ 23.119237] RSP: 002b:00007ffd04a7c9f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 23.119644] RAX: ffffffffffffffda RBX: 00007ffd04a7e0a0 RCX: 00007f744aee2bba [ 23.120023] RDX: 0000000000000040 RSI: 000056488e9e6300 RDI: 0000000000000003 [ 23.120413] RBP: 000056488e9e6300 R08: 00007ffd04a80320 R09: 0000000000000010 [ 23.120809] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000040 [ 23.121219] R13: 00007ffd04a7dc38 R14: 00007ffd04a7ca00 R15: 00007ffd04a7e0a0 [ 23.121617] [ 23.121749] [ 23.121845] The buggy address belongs to the virtual mapping at [ 23.121845] [ffffc90000000000, ffffc90000009000) created by: [ 23.121845] irq_init_percpu_irqstack+0x1cf/0x270 [ 23.122707] [ 23.122803] The buggy address belongs to the physical page: [ 23.123104] page:0000000072ac19f0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24a09 [ 23.123609] flags: 0xfffffc0001000(reserved|node=0|zone=1|lastcpupid=0x1fffff) [ 23.123998] page_type: 0xffffffff() [ 23.124194] raw: 000fffffc0001000 ffffea0000928248 ffffea0000928248 0000000000000000 [ 23.124610] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 [ 23.125023] page dumped because: kasan: bad access detected [ 23.125326] [ 23.125421] Memory state around the buggy address: [ 23.125682] ffffc90000007800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 23.126072] ffffc90000007880: 00 00 00 00 00 f1 f1 f1 f1 f1 f1 00 00 f2 f2 00 [ 23.126455] >ffffc90000007900: 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2 00 00 00 [ 23.126840] ^ [ 23.127138] ffffc90000007980: 00 00 00 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 [ 23.127522] ffffc90000007a00: f3 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 [ 23.127906] ================================================================== [ 23.128324] Disabling lock debugging due to kernel taint Using simple s16 pointers for the 16-bit accesses fixes the problem. For the 32-bit accesses, src and dst can be used directly. Fixes: 96518518cc41 ("netfilter: add nftables") Cc: stable@vger.kernel.org Reported-by: Tanguy DUBROCA (@SidewayRE) from @Synacktiv working with ZDI Signed-off-by: Thadeu Lima de Souza Cascardo Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_byteorder.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nft_byteorder.c b/net/netfilter/nft_byteorder.c index 9a85e797ed58..e596d1a842f7 100644 --- a/net/netfilter/nft_byteorder.c +++ b/net/netfilter/nft_byteorder.c @@ -30,11 +30,11 @@ void nft_byteorder_eval(const struct nft_expr *expr, const struct nft_byteorder *priv = nft_expr_priv(expr); u32 *src = ®s->data[priv->sreg]; u32 *dst = ®s->data[priv->dreg]; - union { u32 u32; u16 u16; } *s, *d; + u16 *s16, *d16; unsigned int i; - s = (void *)src; - d = (void *)dst; + s16 = (void *)src; + d16 = (void *)dst; switch (priv->size) { case 8: { @@ -62,11 +62,11 @@ void nft_byteorder_eval(const struct nft_expr *expr, switch (priv->op) { case NFT_BYTEORDER_NTOH: for (i = 0; i < priv->len / 4; i++) - d[i].u32 = ntohl((__force __be32)s[i].u32); + dst[i] = ntohl((__force __be32)src[i]); break; case NFT_BYTEORDER_HTON: for (i = 0; i < priv->len / 4; i++) - d[i].u32 = (__force __u32)htonl(s[i].u32); + dst[i] = (__force __u32)htonl(src[i]); break; } break; @@ -74,11 +74,11 @@ void nft_byteorder_eval(const struct nft_expr *expr, switch (priv->op) { case NFT_BYTEORDER_NTOH: for (i = 0; i < priv->len / 2; i++) - d[i].u16 = ntohs((__force __be16)s[i].u16); + d16[i] = ntohs((__force __be16)s16[i]); break; case NFT_BYTEORDER_HTON: for (i = 0; i < priv->len / 2; i++) - d[i].u16 = (__force __u16)htons(s[i].u16); + d16[i] = (__force __u16)htons(s16[i]); break; } break; -- cgit v1.2.3