From c4ab9da85b9df3692f861512fe6c9812f38b7471 Mon Sep 17 00:00:00 2001 From: Davide Ornaghi Date: Wed, 5 Jun 2024 13:03:45 +0200 Subject: [PATCH 1/3] netfilter: nft_inner: validate mandatory meta and payload Check for mandatory netlink attributes in payload and meta expression when used embedded from the inner expression, otherwise NULL pointer dereference is possible from userspace. Fixes: a150d122b6bd ("netfilter: nft_meta: add inner match support") Fixes: 3a07327d10a0 ("netfilter: nft_inner: support for inner tunnel header matching") Signed-off-by: Davide Ornaghi Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_meta.c | 3 +++ net/netfilter/nft_payload.c | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c index ba0d3683a45d..9139ce38ea7b 100644 --- a/net/netfilter/nft_meta.c +++ b/net/netfilter/nft_meta.c @@ -839,6 +839,9 @@ static int nft_meta_inner_init(const struct nft_ctx *ctx, struct nft_meta *priv = nft_expr_priv(expr); unsigned int len; + if (!tb[NFTA_META_KEY] || !tb[NFTA_META_DREG]) + return -EINVAL; + priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); switch (priv->key) { case NFT_META_PROTOCOL: diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 0c43d748e23a..50429cbd42da 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -650,6 +650,10 @@ static int nft_payload_inner_init(const struct nft_ctx *ctx, struct nft_payload *priv = nft_expr_priv(expr); u32 base; + if (!tb[NFTA_PAYLOAD_BASE] || !tb[NFTA_PAYLOAD_OFFSET] || + !tb[NFTA_PAYLOAD_LEN] || !tb[NFTA_PAYLOAD_DREG]) + return -EINVAL; + base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); switch (base) { case NFT_PAYLOAD_TUN_HEADER: From 4e7aaa6b82d63e8ddcbfb56b4fd3d014ca586f10 Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Tue, 4 Jun 2024 15:58:03 +0200 Subject: [PATCH 2/3] netfilter: ipset: Fix race between namespace cleanup and gc in the list:set type Lion Ackermann reported that there is a race condition between namespace cleanup in ipset and the garbage collection of the list:set type. The namespace cleanup can destroy the list:set type of sets while the gc of the set type is waiting to run in rcu cleanup. The latter uses data from the destroyed set which thus leads use after free. The patch contains the following parts: - When destroying all sets, first remove the garbage collectors, then wait if needed and then destroy the sets. - Fix the badly ordered "wait then remove gc" for the destroy a single set case. - Fix the missing rcu locking in the list:set type in the userspace test case. - Use proper RCU list handlings in the list:set type. The patch depends on c1193d9bbbd3 (netfilter: ipset: Add list flush to cancel_gc). Fixes: 97f7cf1cd80e (netfilter: ipset: fix performance regression in swap operation) Reported-by: Lion Ackermann Tested-by: Lion Ackermann Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_core.c | 81 +++++++++++++++------------ net/netfilter/ipset/ip_set_list_set.c | 30 +++++----- 2 files changed, 60 insertions(+), 51 deletions(-) diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c index 3184cc6be4c9..c7ae4d9bf3d2 100644 --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -1172,23 +1172,50 @@ ip_set_setname_policy[IPSET_ATTR_CMD_MAX + 1] = { .len = IPSET_MAXNAMELEN - 1 }, }; +/* In order to return quickly when destroying a single set, it is split + * into two stages: + * - Cancel garbage collector + * - Destroy the set itself via call_rcu() + */ + static void -ip_set_destroy_set(struct ip_set *set) +ip_set_destroy_set_rcu(struct rcu_head *head) { - pr_debug("set: %s\n", set->name); + struct ip_set *set = container_of(head, struct ip_set, rcu); - /* Must call it without holding any lock */ set->variant->destroy(set); module_put(set->type->me); kfree(set); } static void -ip_set_destroy_set_rcu(struct rcu_head *head) +_destroy_all_sets(struct ip_set_net *inst) { - struct ip_set *set = container_of(head, struct ip_set, rcu); + struct ip_set *set; + ip_set_id_t i; + bool need_wait = false; - ip_set_destroy_set(set); + /* First cancel gc's: set:list sets are flushed as well */ + for (i = 0; i < inst->ip_set_max; i++) { + set = ip_set(inst, i); + if (set) { + set->variant->cancel_gc(set); + if (set->type->features & IPSET_TYPE_NAME) + need_wait = true; + } + } + /* Must wait for flush to be really finished */ + if (need_wait) + rcu_barrier(); + for (i = 0; i < inst->ip_set_max; i++) { + set = ip_set(inst, i); + if (set) { + ip_set(inst, i) = NULL; + set->variant->destroy(set); + module_put(set->type->me); + kfree(set); + } + } } static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info, @@ -1202,11 +1229,10 @@ static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info, if (unlikely(protocol_min_failed(attr))) return -IPSET_ERR_PROTOCOL; - /* Commands are serialized and references are * protected by the ip_set_ref_lock. * External systems (i.e. xt_set) must call - * ip_set_put|get_nfnl_* functions, that way we + * ip_set_nfnl_get_* functions, that way we * can safely check references here. * * list:set timer can only decrement the reference @@ -1214,8 +1240,6 @@ static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info, * without holding the lock. */ if (!attr[IPSET_ATTR_SETNAME]) { - /* Must wait for flush to be really finished in list:set */ - rcu_barrier(); read_lock_bh(&ip_set_ref_lock); for (i = 0; i < inst->ip_set_max; i++) { s = ip_set(inst, i); @@ -1226,15 +1250,7 @@ static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info, } inst->is_destroyed = true; read_unlock_bh(&ip_set_ref_lock); - for (i = 0; i < inst->ip_set_max; i++) { - s = ip_set(inst, i); - if (s) { - ip_set(inst, i) = NULL; - /* Must cancel garbage collectors */ - s->variant->cancel_gc(s); - ip_set_destroy_set(s); - } - } + _destroy_all_sets(inst); /* Modified by ip_set_destroy() only, which is serialized */ inst->is_destroyed = false; } else { @@ -1255,12 +1271,12 @@ static int ip_set_destroy(struct sk_buff *skb, const struct nfnl_info *info, features = s->type->features; ip_set(inst, i) = NULL; read_unlock_bh(&ip_set_ref_lock); + /* Must cancel garbage collectors */ + s->variant->cancel_gc(s); if (features & IPSET_TYPE_NAME) { /* Must wait for flush to be really finished */ rcu_barrier(); } - /* Must cancel garbage collectors */ - s->variant->cancel_gc(s); call_rcu(&s->rcu, ip_set_destroy_set_rcu); } return 0; @@ -2365,30 +2381,25 @@ ip_set_net_init(struct net *net) } static void __net_exit -ip_set_net_exit(struct net *net) +ip_set_net_pre_exit(struct net *net) { struct ip_set_net *inst = ip_set_pernet(net); - struct ip_set *set = NULL; - ip_set_id_t i; - inst->is_deleted = true; /* flag for ip_set_nfnl_put */ +} - nfnl_lock(NFNL_SUBSYS_IPSET); - for (i = 0; i < inst->ip_set_max; i++) { - set = ip_set(inst, i); - if (set) { - ip_set(inst, i) = NULL; - set->variant->cancel_gc(set); - ip_set_destroy_set(set); - } - } - nfnl_unlock(NFNL_SUBSYS_IPSET); +static void __net_exit +ip_set_net_exit(struct net *net) +{ + struct ip_set_net *inst = ip_set_pernet(net); + + _destroy_all_sets(inst); kvfree(rcu_dereference_protected(inst->ip_set_list, 1)); } static struct pernet_operations ip_set_net_ops = { .init = ip_set_net_init, + .pre_exit = ip_set_net_pre_exit, .exit = ip_set_net_exit, .id = &ip_set_net_id, .size = sizeof(struct ip_set_net), diff --git a/net/netfilter/ipset/ip_set_list_set.c b/net/netfilter/ipset/ip_set_list_set.c index 54e2a1dd7f5f..bfae7066936b 100644 --- a/net/netfilter/ipset/ip_set_list_set.c +++ b/net/netfilter/ipset/ip_set_list_set.c @@ -79,7 +79,7 @@ list_set_kadd(struct ip_set *set, const struct sk_buff *skb, struct set_elem *e; int ret; - list_for_each_entry(e, &map->members, list) { + list_for_each_entry_rcu(e, &map->members, list) { if (SET_WITH_TIMEOUT(set) && ip_set_timeout_expired(ext_timeout(e, set))) continue; @@ -99,7 +99,7 @@ list_set_kdel(struct ip_set *set, const struct sk_buff *skb, struct set_elem *e; int ret; - list_for_each_entry(e, &map->members, list) { + list_for_each_entry_rcu(e, &map->members, list) { if (SET_WITH_TIMEOUT(set) && ip_set_timeout_expired(ext_timeout(e, set))) continue; @@ -188,9 +188,10 @@ list_set_utest(struct ip_set *set, void *value, const struct ip_set_ext *ext, struct list_set *map = set->data; struct set_adt_elem *d = value; struct set_elem *e, *next, *prev = NULL; - int ret; + int ret = 0; - list_for_each_entry(e, &map->members, list) { + rcu_read_lock(); + list_for_each_entry_rcu(e, &map->members, list) { if (SET_WITH_TIMEOUT(set) && ip_set_timeout_expired(ext_timeout(e, set))) continue; @@ -201,6 +202,7 @@ list_set_utest(struct ip_set *set, void *value, const struct ip_set_ext *ext, if (d->before == 0) { ret = 1; + goto out; } else if (d->before > 0) { next = list_next_entry(e, list); ret = !list_is_last(&e->list, &map->members) && @@ -208,9 +210,11 @@ list_set_utest(struct ip_set *set, void *value, const struct ip_set_ext *ext, } else { ret = prev && prev->id == d->refid; } - return ret; + goto out; } - return 0; +out: + rcu_read_unlock(); + return ret; } static void @@ -239,7 +243,7 @@ list_set_uadd(struct ip_set *set, void *value, const struct ip_set_ext *ext, /* Find where to add the new entry */ n = prev = next = NULL; - list_for_each_entry(e, &map->members, list) { + list_for_each_entry_rcu(e, &map->members, list) { if (SET_WITH_TIMEOUT(set) && ip_set_timeout_expired(ext_timeout(e, set))) continue; @@ -316,9 +320,9 @@ list_set_udel(struct ip_set *set, void *value, const struct ip_set_ext *ext, { struct list_set *map = set->data; struct set_adt_elem *d = value; - struct set_elem *e, *next, *prev = NULL; + struct set_elem *e, *n, *next, *prev = NULL; - list_for_each_entry(e, &map->members, list) { + list_for_each_entry_safe(e, n, &map->members, list) { if (SET_WITH_TIMEOUT(set) && ip_set_timeout_expired(ext_timeout(e, set))) continue; @@ -424,14 +428,8 @@ static void list_set_destroy(struct ip_set *set) { struct list_set *map = set->data; - struct set_elem *e, *n; - list_for_each_entry_safe(e, n, &map->members, list) { - list_del(&e->list); - ip_set_put_byindex(map->net, e->id); - ip_set_ext_destroy(set, e); - kfree(e); - } + WARN_ON_ONCE(!list_empty(&map->members)); kfree(map); set->data = NULL; From 6f8f132cc7bac2ac76911e47d5baa378aafda4cb Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 6 Jun 2024 12:23:31 +0200 Subject: [PATCH 3/3] netfilter: Use flowlabel flow key when re-routing mangled packets 'ip6 dscp set $v' in an nftables outpute route chain has no effect. While nftables does detect the dscp change and calls the reroute hook. But ip6_route_me_harder never sets the dscp/flowlabel: flowlabel/dsfield routing rules are ignored and no reroute takes place. Thanks to Yi Chen for an excellent reproducer script that I used to validate this change. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Yi Chen Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c index 53d255838e6a..5d989d803009 100644 --- a/net/ipv6/netfilter.c +++ b/net/ipv6/netfilter.c @@ -36,6 +36,7 @@ int ip6_route_me_harder(struct net *net, struct sock *sk_partial, struct sk_buff .flowi6_uid = sock_net_uid(net, sk), .daddr = iph->daddr, .saddr = iph->saddr, + .flowlabel = ip6_flowinfo(iph), }; int err;