[PATCH 0/9] Netfilter updates for net

[PATCH 0/9] Netfilter updates for net

[Pablo Neira Ayuso]

Hello,

The following patchset contains Netfilter fixes for net:

1) Fix use-after-free in ipset bitmap destroy path, from Cong Wang.

2) Missing init netns in entry cleanup path of arp_tables,
   from Florian Westphal.

3) Fix WARN_ON in set destroy path due to missing cleanup on
   transaction error.

4) Incorrect netlink sanity check in tunnel, from Florian Westphal.

5) Missing sanity check for erspan version netlink attribute, also
   from Florian.

6) Remove WARN in nft_request_module() that can be triggered from
   userspace, from Florian Westphal.

7) Memleak in NFTA_HOOK_DEVS netlink parser, from Dan Carpenter.

8) List poison from commit path for flowtables that are added and
   deleted in the same batch, from Florian Westphal.

9) Fix NAT ICMP packet corruption, from Eyal Birger.

You can pull these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git

Thank you.

----------------------------------------------------------------

The following changes since commit c9f53049d4a842db6bcd76f597759a0ef5f65c86:

  MAINTAINERS: update my email address (2020-01-11 14:33:39 -0800)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git HEAD

for you to fetch changes up to 61177e911dad660df86a4553eb01c95ece2f6a82:

  netfilter: nat: fix ICMP header corruption on ICMP errors (2020-01-16 15:08:25 +0100)

----------------------------------------------------------------
Cong Wang (1):
      netfilter: fix a use-after-free in mtype_destroy()

Dan Carpenter (1):
      netfilter: nf_tables: fix memory leak in nf_tables_parse_netdev_hooks()

Eyal Birger (1):
      netfilter: nat: fix ICMP header corruption on ICMP errors

Florian Westphal (5):
      netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct
      netfilter: nft_tunnel: fix null-attribute check
      netfilter: nft_tunnel: ERSPAN_VERSION must not be null
      netfilter: nf_tables: remove WARN and add NLA_STRING upper limits
      netfilter: nf_tables: fix flowtable list del corruption

Pablo Neira Ayuso (1):
      netfilter: nf_tables: store transaction list locally while requesting module

 net/ipv4/netfilter/arp_tables.c         | 19 ++++++++--------
 net/netfilter/ipset/ip_set_bitmap_gen.h |  2 +-
 net/netfilter/nf_nat_proto.c            | 13 +++++++++++
 net/netfilter/nf_tables_api.c           | 39 ++++++++++++++++++++++-----------
 net/netfilter/nft_tunnel.c              |  5 ++++-
 5 files changed, 54 insertions(+), 24 deletions(-)

[PATCH 1/9] netfilter: fix a use-after-free in mtype_destroy()

[Pablo Neira Ayuso]

From: Cong Wang <xiyou.wangcong@gmail.com>

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 <kadlec@netfilter.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 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;
-- 
2.11.0

[PATCH 2/9] netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 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. */
-- 
2.11.0

[PATCH 3/9] netfilter: nf_tables: store transaction list locally while requesting module

[Pablo Neira Ayuso]

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 <marco.oliverio@tanaza.com>
Fixes: 452238e8d5ff ("netfilter: nf_tables: add and use helper for module autoload")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 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
 
-- 
2.11.0

[PATCH 4/9] netfilter: nft_tunnel: fix null-attribute check

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 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;
 
-- 
2.11.0

[PATCH 5/9] netfilter: nft_tunnel: ERSPAN_VERSION must not be null

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

Fixes: af308b94a2a4a5 ("netfilter: nf_tables: add tunnel support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 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:
-- 
2.11.0

[PATCH 6/9] netfilter: nf_tables: remove WARN and add NLA_STRING upper limits

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 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 <net/net_namespace.h>
 #include <net/sock.h>
 
+#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] = {
-- 
2.11.0

[PATCH 7/9] netfilter: nf_tables: fix memory leak in nf_tables_parse_netdev_hooks()

[Pablo Neira Ayuso]

From: Dan Carpenter <dan.carpenter@oracle.com>

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 <dan.carpenter@oracle.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 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;
 		}
-- 
2.11.0

[PATCH 8/9] netfilter: nf_tables: fix flowtable list del corruption

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 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;
-- 
2.11.0

[PATCH 9/9] netfilter: nat: fix ICMP header corruption on ICMP errors

[Pablo Neira Ayuso]

From: Eyal Birger <eyal.birger@gmail.com>

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 <shmulik.ladkani@gmail.com>
Fixes: 8303b7e8f018 ("netfilter: nat: fix spurious connection timeouts")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 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;
-- 
2.11.0

Re: [PATCH 0/9] Netfilter updates for net

[David Miller]

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Thu, 16 Jan 2020 20:50:35 +0100

> The following patchset contains Netfilter fixes for net:
 ...
> You can pull these changes from:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git

Pulled, thanks Pablo.