From cfbe3650dd3ef2ea9a4420ca89d9a4df98af3fb6 Mon Sep 17 00:00:00 2001 From: Dongliang Mu Date: Wed, 14 Jul 2021 11:27:03 +0800 Subject: [PATCH 1/6] netfilter: nf_tables: fix audit memory leak in nf_tables_commit In nf_tables_commit, if nf_tables_commit_audit_alloc fails, it does not free the adp variable. Fix this by adding nf_tables_commit_audit_free which frees the linked list with the head node adl. backtrace: kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] nf_tables_commit_audit_alloc net/netfilter/nf_tables_api.c:8439 [inline] nf_tables_commit+0x16e/0x1760 net/netfilter/nf_tables_api.c:8508 nfnetlink_rcv_batch+0x512/0xa80 net/netfilter/nfnetlink.c:562 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] nfnetlink_rcv+0x1fa/0x220 net/netfilter/nfnetlink.c:652 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x2c7/0x3e0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x36b/0x6b0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:702 [inline] sock_sendmsg+0x56/0x80 net/socket.c:722 Reported-by: syzbot Reported-by: kernel test robot Fixes: c520292f29b8 ("audit: log nftables configuration change events once per table") Signed-off-by: Dongliang Mu Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index de182d1f7c4e..081437dd75b7 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8445,6 +8445,16 @@ static int nf_tables_commit_audit_alloc(struct list_head *adl, return 0; } +static void nf_tables_commit_audit_free(struct list_head *adl) +{ + struct nft_audit_data *adp, *adn; + + list_for_each_entry_safe(adp, adn, adl, list) { + list_del(&adp->list); + kfree(adp); + } +} + static void nf_tables_commit_audit_collect(struct list_head *adl, struct nft_table *table, u32 op) { @@ -8509,6 +8519,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) ret = nf_tables_commit_audit_alloc(&adl, trans->ctx.table); if (ret) { nf_tables_commit_chain_prepare_cancel(net); + nf_tables_commit_audit_free(&adl); return ret; } if (trans->msg_type == NFT_MSG_NEWRULE || @@ -8518,6 +8529,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) ret = nf_tables_commit_chain_prepare(net, chain); if (ret < 0) { nf_tables_commit_chain_prepare_cancel(net); + nf_tables_commit_audit_free(&adl); return ret; } } From 32c3973d808301e7a980f80fee8818fdf7c82b09 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sat, 17 Jul 2021 10:10:29 +0200 Subject: [PATCH 2/6] netfilter: flowtable: avoid possible false sharing The flowtable follows the same timeout approach as conntrack, use the same idiom as in cc16921351d8 ("netfilter: conntrack: avoid same-timeout update") but also include the fix provided by e37542ba111f ("netfilter: conntrack: avoid possible false sharing"). Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_flow_table_core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c index 1e50908b1b7e..551976e4284c 100644 --- a/net/netfilter/nf_flow_table_core.c +++ b/net/netfilter/nf_flow_table_core.c @@ -331,7 +331,11 @@ EXPORT_SYMBOL_GPL(flow_offload_add); void flow_offload_refresh(struct nf_flowtable *flow_table, struct flow_offload *flow) { - flow->timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow); + u32 timeout; + + timeout = nf_flowtable_time_stamp + flow_offload_get_timeout(flow); + if (READ_ONCE(flow->timeout) != timeout) + WRITE_ONCE(flow->timeout, timeout); if (likely(!nf_flowtable_hw_offload(flow_table))) return; From 32953df7a6eb56bd9b8f18a13034d55f9fc96cfa Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sat, 17 Jul 2021 10:20:08 +0200 Subject: [PATCH 3/6] netfilter: nft_last: avoid possible false sharing Use the idiom described in: https://github.com/google/ktsan/wiki/READ_ONCE-and-WRITE_ONCE#it-may-improve-performance Moreover, prevent a compiler optimization. Fixes: 836382dc2471 ("netfilter: nf_tables: add last expression") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_last.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/net/netfilter/nft_last.c b/net/netfilter/nft_last.c index 8088b99f2ee3..304e33cbed9b 100644 --- a/net/netfilter/nft_last.c +++ b/net/netfilter/nft_last.c @@ -48,24 +48,30 @@ static void nft_last_eval(const struct nft_expr *expr, { struct nft_last_priv *priv = nft_expr_priv(expr); - priv->last_jiffies = jiffies; - priv->last_set = 1; + if (READ_ONCE(priv->last_jiffies) != jiffies) + WRITE_ONCE(priv->last_jiffies, jiffies); + if (READ_ONCE(priv->last_set) == 0) + WRITE_ONCE(priv->last_set, 1); } static int nft_last_dump(struct sk_buff *skb, const struct nft_expr *expr) { struct nft_last_priv *priv = nft_expr_priv(expr); + unsigned long last_jiffies = READ_ONCE(priv->last_jiffies); + u32 last_set = READ_ONCE(priv->last_set); __be64 msecs; - if (time_before(jiffies, priv->last_jiffies)) - priv->last_set = 0; + if (time_before(jiffies, last_jiffies)) { + WRITE_ONCE(priv->last_set, 0); + last_set = 0; + } - if (priv->last_set) - msecs = nf_jiffies64_to_msecs(jiffies - priv->last_jiffies); + if (last_set) + msecs = nf_jiffies64_to_msecs(jiffies - last_jiffies); else msecs = 0; - if (nla_put_be32(skb, NFTA_LAST_SET, htonl(priv->last_set)) || + if (nla_put_be32(skb, NFTA_LAST_SET, htonl(last_set)) || nla_put_be64(skb, NFTA_LAST_MSECS, msecs, NFTA_LAST_PAD)) goto nla_put_failure; From 30a56a2b881821625f79837d4d968c679852444e Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Sun, 18 Jul 2021 18:36:00 +0200 Subject: [PATCH 4/6] netfilter: conntrack: adjust stop timestamp to real expiry value In case the entry is evicted via garbage collection there is delay between the timeout value and the eviction event. This adjusts the stop value based on how much time has passed. Fixes: b87a2f9199ea82 ("netfilter: conntrack: add gc worker to remove timed-out entries") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 83c52df85870..5c03e5106751 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -670,8 +670,13 @@ bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report) return false; tstamp = nf_conn_tstamp_find(ct); - if (tstamp && tstamp->stop == 0) + if (tstamp) { + s32 timeout = ct->timeout - nfct_time_stamp; + tstamp->stop = ktime_get_real_ns(); + if (timeout < 0) + tstamp->stop -= jiffies_to_nsecs(-timeout); + } if (nf_conntrack_event_report(IPCT_DESTROY, ct, portid, report) < 0) { From a33f387ecd5aafae514095c2c4a8c24f7aea7e8b Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 20 Jul 2021 18:22:50 +0200 Subject: [PATCH 5/6] netfilter: nft_nat: allow to specify layer 4 protocol NAT only nft_nat reports a bogus EAFNOSUPPORT if no layer 3 information is specified. Fixes: d07db9884a5f ("netfilter: nf_tables: introduce nft_validate_register_load()") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_nat.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nft_nat.c b/net/netfilter/nft_nat.c index 0840c635b752..be1595d6979d 100644 --- a/net/netfilter/nft_nat.c +++ b/net/netfilter/nft_nat.c @@ -201,7 +201,9 @@ static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr, alen = sizeof_field(struct nf_nat_range, min_addr.ip6); break; default: - return -EAFNOSUPPORT; + if (tb[NFTA_NAT_REG_ADDR_MIN]) + return -EAFNOSUPPORT; + break; } priv->family = family; From 217e26bd87b2930856726b48a4e71c768b8c9bf5 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 21 Jul 2021 17:22:32 +0200 Subject: [PATCH 6/6] netfilter: nfnl_hook: fix unused variable warning The only user of this variable is in an #ifdef: net/netfilter/nfnetlink_hook.c: In function 'nfnl_hook_entries_head': net/netfilter/nfnetlink_hook.c:177:28: error: unused variable 'netdev' [-Werror=unused-variable] Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Arnd Bergmann Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink_hook.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/netfilter/nfnetlink_hook.c b/net/netfilter/nfnetlink_hook.c index 50b4e3c9347a..202f57d17bab 100644 --- a/net/netfilter/nfnetlink_hook.c +++ b/net/netfilter/nfnetlink_hook.c @@ -174,7 +174,9 @@ static const struct nf_hook_entries * nfnl_hook_entries_head(u8 pf, unsigned int hook, struct net *net, const char *dev) { const struct nf_hook_entries *hook_head = NULL; +#ifdef CONFIG_NETFILTER_INGRESS struct net_device *netdev; +#endif switch (pf) { case NFPROTO_IPV4: