From c120959387efa51479056fd01dc90adfba7a590c Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Fri, 10 Jan 2020 11:53:08 -0800 Subject: [PATCH 1/9] netfilter: fix a use-after-free in mtype_destroy() map->members is freed by ip_set_free() right before using it in mtype_ext_cleanup() again. So we just have to move it down. Reported-by: syzbot+4c3cc6dbe7259dbf9054@syzkaller.appspotmail.com Fixes: 40cd63bf33b2 ("netfilter: ipset: Support extensions which need a per data destroy function") Acked-by: Jozsef Kadlecsik Signed-off-by: Cong Wang Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_bitmap_gen.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/ipset/ip_set_bitmap_gen.h b/net/netfilter/ipset/ip_set_bitmap_gen.h index 1abd6f0dc227..077a2cb65fcb 100644 --- a/net/netfilter/ipset/ip_set_bitmap_gen.h +++ b/net/netfilter/ipset/ip_set_bitmap_gen.h @@ -60,9 +60,9 @@ mtype_destroy(struct ip_set *set) if (SET_WITH_TIMEOUT(set)) del_timer_sync(&map->gc); - ip_set_free(map->members); if (set->dsize && set->extensions & IPSET_EXT_DESTROY) mtype_ext_cleanup(set); + ip_set_free(map->members); ip_set_free(map); set->data = NULL; From 212e7f56605ef9688d0846db60c6c6ec06544095 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Sat, 11 Jan 2020 23:19:53 +0100 Subject: [PATCH 2/9] netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct An earlier commit (1b789577f655060d98d20e, "netfilter: arp_tables: init netns pointer in xt_tgchk_param struct") fixed missing net initialization for arptables, but turns out it was incomplete. We can get a very similar struct net NULL deref during error unwinding: general protection fault: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:xt_rateest_put+0xa1/0x440 net/netfilter/xt_RATEEST.c:77 xt_rateest_tg_destroy+0x72/0xa0 net/netfilter/xt_RATEEST.c:175 cleanup_entry net/ipv4/netfilter/arp_tables.c:509 [inline] translate_table+0x11f4/0x1d80 net/ipv4/netfilter/arp_tables.c:587 do_replace net/ipv4/netfilter/arp_tables.c:981 [inline] do_arpt_set_ctl+0x317/0x650 net/ipv4/netfilter/arp_tables.c:1461 Also init the netns pointer in xt_tgdtor_param struct. Fixes: add67461240c1d ("netfilter: add struct net * to target parameters") Reported-by: syzbot+91bdd8eece0f6629ec8b@syzkaller.appspotmail.com Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/arp_tables.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 069f72edb264..f1f78a742b36 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -496,12 +496,13 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e, return 0; } -static inline void cleanup_entry(struct arpt_entry *e) +static void cleanup_entry(struct arpt_entry *e, struct net *net) { struct xt_tgdtor_param par; struct xt_entry_target *t; t = arpt_get_target(e); + par.net = net; par.target = t->u.kernel.target; par.targinfo = t->data; par.family = NFPROTO_ARP; @@ -584,7 +585,7 @@ static int translate_table(struct net *net, xt_entry_foreach(iter, entry0, newinfo->size) { if (i-- == 0) break; - cleanup_entry(iter); + cleanup_entry(iter, net); } return ret; } @@ -927,7 +928,7 @@ static int __do_replace(struct net *net, const char *name, /* Decrease module usage counts and free resource */ loc_cpu_old_entry = oldinfo->entries; xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size) - cleanup_entry(iter); + cleanup_entry(iter, net); xt_free_table_info(oldinfo); if (copy_to_user(counters_ptr, counters, @@ -990,7 +991,7 @@ static int do_replace(struct net *net, const void __user *user, free_newinfo_untrans: xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) - cleanup_entry(iter); + cleanup_entry(iter, net); free_newinfo: xt_free_table_info(newinfo); return ret; @@ -1287,7 +1288,7 @@ static int compat_do_replace(struct net *net, void __user *user, free_newinfo_untrans: xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) - cleanup_entry(iter); + cleanup_entry(iter, net); free_newinfo: xt_free_table_info(newinfo); return ret; @@ -1514,7 +1515,7 @@ static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len return ret; } -static void __arpt_unregister_table(struct xt_table *table) +static void __arpt_unregister_table(struct net *net, struct xt_table *table) { struct xt_table_info *private; void *loc_cpu_entry; @@ -1526,7 +1527,7 @@ static void __arpt_unregister_table(struct xt_table *table) /* Decrease module usage counts and free resources */ loc_cpu_entry = private->entries; xt_entry_foreach(iter, loc_cpu_entry, private->size) - cleanup_entry(iter); + cleanup_entry(iter, net); if (private->number > private->initial_entries) module_put(table_owner); xt_free_table_info(private); @@ -1566,7 +1567,7 @@ int arpt_register_table(struct net *net, ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks)); if (ret != 0) { - __arpt_unregister_table(new_table); + __arpt_unregister_table(net, new_table); *res = NULL; } @@ -1581,7 +1582,7 @@ void arpt_unregister_table(struct net *net, struct xt_table *table, const struct nf_hook_ops *ops) { nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks)); - __arpt_unregister_table(table); + __arpt_unregister_table(net, table); } /* The built-in targets: standard (NULL) and error. */ From ec7470b834fe7b5d7eff11b6677f5d7fdf5e9a91 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 13 Jan 2020 18:09:58 +0100 Subject: [PATCH 3/9] netfilter: nf_tables: store transaction list locally while requesting module This patch fixes a WARN_ON in nft_set_destroy() due to missing set reference count drop from the preparation phase. This is triggered by the module autoload path. Do not exercise the abort path from nft_request_module() while preparation phase cleaning up is still pending. WARNING: CPU: 3 PID: 3456 at net/netfilter/nf_tables_api.c:3740 nft_set_destroy+0x45/0x50 [nf_tables] [...] CPU: 3 PID: 3456 Comm: nft Not tainted 5.4.6-arch3-1 #1 RIP: 0010:nft_set_destroy+0x45/0x50 [nf_tables] Code: e8 30 eb 83 c6 48 8b 85 80 00 00 00 48 8b b8 90 00 00 00 e8 dd 6b d7 c5 48 8b 7d 30 e8 24 dd eb c5 48 89 ef 5d e9 6b c6 e5 c5 <0f> 0b c3 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8b 7f 10 e9 52 RSP: 0018:ffffac4f43e53700 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff99d63a154d80 RCX: 0000000001f88e03 RDX: 0000000001f88c03 RSI: ffff99d6560ef0c0 RDI: ffff99d63a101200 RBP: ffff99d617721de0 R08: 0000000000000000 R09: 0000000000000318 R10: 00000000f0000000 R11: 0000000000000001 R12: ffffffff880fabf0 R13: dead000000000122 R14: dead000000000100 R15: ffff99d63a154d80 FS: 00007ff3dbd5b740(0000) GS:ffff99d6560c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00001cb5de6a9000 CR3: 000000016eb6a004 CR4: 00000000001606e0 Call Trace: __nf_tables_abort+0x3e3/0x6d0 [nf_tables] nft_request_module+0x6f/0x110 [nf_tables] nft_expr_type_request_module+0x28/0x50 [nf_tables] nf_tables_expr_parse+0x198/0x1f0 [nf_tables] nft_expr_init+0x3b/0xf0 [nf_tables] nft_dynset_init+0x1e2/0x410 [nf_tables] nf_tables_newrule+0x30a/0x930 [nf_tables] nfnetlink_rcv_batch+0x2a0/0x640 [nfnetlink] nfnetlink_rcv+0x125/0x171 [nfnetlink] netlink_unicast+0x179/0x210 netlink_sendmsg+0x208/0x3d0 sock_sendmsg+0x5e/0x60 ____sys_sendmsg+0x21b/0x290 Update comment on the code to describe the new behaviour. Reported-by: Marco Oliverio Fixes: 452238e8d5ff ("netfilter: nf_tables: add and use helper for module autoload") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 43f05b3acd60..168765d1d1c2 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -564,23 +564,21 @@ __nf_tables_chain_type_lookup(const struct nlattr *nla, u8 family) } /* - * Loading a module requires dropping mutex that guards the - * transaction. - * We first need to abort any pending transactions as once - * mutex is unlocked a different client could start a new - * transaction. It must not see any 'future generation' - * changes * as these changes will never happen. + * Loading a module requires dropping mutex that guards the transaction. + * A different client might race to start a new transaction meanwhile. Zap the + * list of pending transaction and then restore it once the mutex is grabbed + * again. Users of this function return EAGAIN which implicitly triggers the + * transaction abort path to clean up the list of pending transactions. */ #ifdef CONFIG_MODULES -static int __nf_tables_abort(struct net *net); - static void nft_request_module(struct net *net, const char *fmt, ...) { char module_name[MODULE_NAME_LEN]; + LIST_HEAD(commit_list); va_list args; int ret; - __nf_tables_abort(net); + list_splice_init(&net->nft.commit_list, &commit_list); va_start(args, fmt); ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); @@ -591,6 +589,9 @@ static void nft_request_module(struct net *net, const char *fmt, ...) mutex_unlock(&net->nft.commit_mutex); request_module("%s", module_name); mutex_lock(&net->nft.commit_mutex); + + WARN_ON_ONCE(!list_empty(&net->nft.commit_list)); + list_splice(&commit_list, &net->nft.commit_list); } #endif From 1c702bf902bd37349f6d91cd7f4b372b1e46d0ed Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 16 Jan 2020 08:44:11 +0100 Subject: [PATCH 4/9] netfilter: nft_tunnel: fix null-attribute check else we get null deref when one of the attributes is missing, both must be non-null. Reported-by: syzbot+76d0b80493ac881ff77b@syzkaller.appspotmail.com Fixes: aaecfdb5c5dd8ba ("netfilter: nf_tables: match on tunnel metadata") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_tunnel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nft_tunnel.c b/net/netfilter/nft_tunnel.c index 3d4c2ae605a8..d89c7c553030 100644 --- a/net/netfilter/nft_tunnel.c +++ b/net/netfilter/nft_tunnel.c @@ -76,7 +76,7 @@ static int nft_tunnel_get_init(const struct nft_ctx *ctx, struct nft_tunnel *priv = nft_expr_priv(expr); u32 len; - if (!tb[NFTA_TUNNEL_KEY] && + if (!tb[NFTA_TUNNEL_KEY] || !tb[NFTA_TUNNEL_DREG]) return -EINVAL; From 9ec22d7c6c69146180577f3ad5fdf504beeaee62 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 16 Jan 2020 08:58:05 +0100 Subject: [PATCH 5/9] netfilter: nft_tunnel: ERSPAN_VERSION must not be null Fixes: af308b94a2a4a5 ("netfilter: nf_tables: add tunnel support") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_tunnel.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/nft_tunnel.c b/net/netfilter/nft_tunnel.c index d89c7c553030..5284fcf16be7 100644 --- a/net/netfilter/nft_tunnel.c +++ b/net/netfilter/nft_tunnel.c @@ -266,6 +266,9 @@ static int nft_tunnel_obj_erspan_init(const struct nlattr *attr, if (err < 0) return err; + if (!tb[NFTA_TUNNEL_KEY_ERSPAN_VERSION]) + return -EINVAL; + version = ntohl(nla_get_be32(tb[NFTA_TUNNEL_KEY_ERSPAN_VERSION])); switch (version) { case ERSPAN_VERSION: From 9332d27d7918182add34e8043f6a754530fdd022 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 16 Jan 2020 09:06:50 +0100 Subject: [PATCH 6/9] netfilter: nf_tables: remove WARN and add NLA_STRING upper limits This WARN can trigger because some of the names fed to the module autoload function can be of arbitrary length. Remove the WARN and add limits for all NLA_STRING attributes. Reported-by: syzbot+0e63ae76d117ae1c3a01@syzkaller.appspotmail.com Fixes: 452238e8d5ffd8 ("netfilter: nf_tables: add and use helper for module autoload") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 168765d1d1c2..b3692458d428 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -22,6 +22,8 @@ #include #include +#define NFT_MODULE_AUTOLOAD_LIMIT (MODULE_NAME_LEN - sizeof("nft-expr-255-")) + static LIST_HEAD(nf_tables_expressions); static LIST_HEAD(nf_tables_objects); static LIST_HEAD(nf_tables_flowtables); @@ -583,7 +585,7 @@ static void nft_request_module(struct net *net, const char *fmt, ...) va_start(args, fmt); ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); va_end(args); - if (WARN(ret >= MODULE_NAME_LEN, "truncated: '%s' (len %d)", module_name, ret)) + if (ret >= MODULE_NAME_LEN) return; mutex_unlock(&net->nft.commit_mutex); @@ -1242,7 +1244,8 @@ static const struct nla_policy nft_chain_policy[NFTA_CHAIN_MAX + 1] = { .len = NFT_CHAIN_MAXNAMELEN - 1 }, [NFTA_CHAIN_HOOK] = { .type = NLA_NESTED }, [NFTA_CHAIN_POLICY] = { .type = NLA_U32 }, - [NFTA_CHAIN_TYPE] = { .type = NLA_STRING }, + [NFTA_CHAIN_TYPE] = { .type = NLA_STRING, + .len = NFT_MODULE_AUTOLOAD_LIMIT }, [NFTA_CHAIN_COUNTERS] = { .type = NLA_NESTED }, [NFTA_CHAIN_FLAGS] = { .type = NLA_U32 }, }; @@ -2356,7 +2359,8 @@ static const struct nft_expr_type *nft_expr_type_get(struct net *net, } static const struct nla_policy nft_expr_policy[NFTA_EXPR_MAX + 1] = { - [NFTA_EXPR_NAME] = { .type = NLA_STRING }, + [NFTA_EXPR_NAME] = { .type = NLA_STRING, + .len = NFT_MODULE_AUTOLOAD_LIMIT }, [NFTA_EXPR_DATA] = { .type = NLA_NESTED }, }; @@ -4199,7 +4203,8 @@ static const struct nla_policy nft_set_elem_policy[NFTA_SET_ELEM_MAX + 1] = { [NFTA_SET_ELEM_USERDATA] = { .type = NLA_BINARY, .len = NFT_USERDATA_MAXLEN }, [NFTA_SET_ELEM_EXPR] = { .type = NLA_NESTED }, - [NFTA_SET_ELEM_OBJREF] = { .type = NLA_STRING }, + [NFTA_SET_ELEM_OBJREF] = { .type = NLA_STRING, + .len = NFT_OBJ_MAXNAMELEN - 1 }, }; static const struct nla_policy nft_set_elem_list_policy[NFTA_SET_ELEM_LIST_MAX + 1] = { From cd77e75b5e4632d05d61fec5383052713c8ede2b Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Thu, 16 Jan 2020 13:09:31 +0300 Subject: [PATCH 7/9] netfilter: nf_tables: fix memory leak in nf_tables_parse_netdev_hooks() Syzbot detected a leak in nf_tables_parse_netdev_hooks(). If the hook already exists, then the error handling doesn't free the newest "hook". Reported-by: syzbot+f9d4095107fc8749c69c@syzkaller.appspotmail.com Fixes: b75a3e8371bc ("netfilter: nf_tables: allow netdevice to be used only once per flowtable") Signed-off-by: Dan Carpenter Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index b3692458d428..896a6e8aff91 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1680,6 +1680,7 @@ static int nf_tables_parse_netdev_hooks(struct net *net, goto err_hook; } if (nft_hook_list_find(hook_list, hook)) { + kfree(hook); err = -EEXIST; goto err_hook; } From 335178d5429c4cee61b58f4ac80688f556630818 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 16 Jan 2020 12:03:01 +0100 Subject: [PATCH 8/9] netfilter: nf_tables: fix flowtable list del corruption syzbot reported following crash: list_del corruption, ffff88808c9bb000->prev is LIST_POISON2 (dead000000000122) [..] Call Trace: __list_del_entry include/linux/list.h:131 [inline] list_del_rcu include/linux/rculist.h:148 [inline] nf_tables_commit+0x1068/0x3b30 net/netfilter/nf_tables_api.c:7183 [..] The commit transaction list has: NFT_MSG_NEWTABLE NFT_MSG_NEWFLOWTABLE NFT_MSG_DELFLOWTABLE NFT_MSG_DELTABLE A missing generation check during DELTABLE processing causes it to queue the DELFLOWTABLE operation a second time, so we corrupt the list here: case NFT_MSG_DELFLOWTABLE: list_del_rcu(&nft_trans_flowtable(trans)->list); nf_tables_flowtable_notify(&trans->ctx, because we have two different DELFLOWTABLE transactions for the same flowtable. We then call list_del_rcu() twice for the same flowtable->list. The object handling seems to suffer from the same bug so add a generation check too and only queue delete transactions for flowtables/objects that are still active in the next generation. Reported-by: syzbot+37a6804945a3a13b1572@syzkaller.appspotmail.com Fixes: 3b49e2e94e6eb ("netfilter: nf_tables: add flow table netlink frontend") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 896a6e8aff91..65f51a2e9c2a 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1048,12 +1048,18 @@ static int nft_flush_table(struct nft_ctx *ctx) } list_for_each_entry_safe(flowtable, nft, &ctx->table->flowtables, list) { + if (!nft_is_active_next(ctx->net, flowtable)) + continue; + err = nft_delflowtable(ctx, flowtable); if (err < 0) goto out; } list_for_each_entry_safe(obj, ne, &ctx->table->objects, list) { + if (!nft_is_active_next(ctx->net, obj)) + continue; + err = nft_delobj(ctx, obj); if (err < 0) goto out; From 61177e911dad660df86a4553eb01c95ece2f6a82 Mon Sep 17 00:00:00 2001 From: Eyal Birger Date: Tue, 14 Jan 2020 10:03:50 +0200 Subject: [PATCH 9/9] netfilter: nat: fix ICMP header corruption on ICMP errors Commit 8303b7e8f018 ("netfilter: nat: fix spurious connection timeouts") made nf_nat_icmp_reply_translation() use icmp_manip_pkt() as the l4 manipulation function for the outer packet on ICMP errors. However, icmp_manip_pkt() assumes the packet has an 'id' field which is not correct for all types of ICMP messages. This is not correct for ICMP error packets, and leads to bogus bytes being written the ICMP header, which can be wrongfully regarded as 'length' bytes by RFC 4884 compliant receivers. Fix by assigning the 'id' field only for ICMP messages that have this semantic. Reported-by: Shmulik Ladkani Fixes: 8303b7e8f018 ("netfilter: nat: fix spurious connection timeouts") Signed-off-by: Eyal Birger Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_nat_proto.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/net/netfilter/nf_nat_proto.c b/net/netfilter/nf_nat_proto.c index 0a59c14b5177..64eedc17037a 100644 --- a/net/netfilter/nf_nat_proto.c +++ b/net/netfilter/nf_nat_proto.c @@ -233,6 +233,19 @@ icmp_manip_pkt(struct sk_buff *skb, return false; hdr = (struct icmphdr *)(skb->data + hdroff); + switch (hdr->type) { + case ICMP_ECHO: + case ICMP_ECHOREPLY: + case ICMP_TIMESTAMP: + case ICMP_TIMESTAMPREPLY: + case ICMP_INFO_REQUEST: + case ICMP_INFO_REPLY: + case ICMP_ADDRESS: + case ICMP_ADDRESSREPLY: + break; + default: + return true; + } inet_proto_csum_replace2(&hdr->checksum, skb, hdr->un.echo.id, tuple->src.u.icmp.id, false); hdr->un.echo.id = tuple->src.u.icmp.id;