[PATCH 0/3] Netfilter fixes for net

[PATCH 0/3] Netfilter fixes for net

[Pablo Neira Ayuso]

Hi David,

The following patchset contains three Netfilter fixes for your net tree,
they are:

* Fix missing generation sequence initialization which results in a splat
  if lockdep is enabled, it was introduced in the recent works to improve
  nf_conntrack scalability, from Andrey Vagin.

* Don't flush the GRE keymap list in nf_conntrack when the pptp helper is
  disabled otherwise this crashes due to a double release, from Andrey
  Vagin.

* Fix nf_tables cmp fast in big endian, from Patrick McHardy.

You can pull these changes from:

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

Thanks!

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

The following changes since commit 6859e7df6d9045a461412777e63bd8cef12f9705:

  netdev: remove potentially harmful checks (2014-04-07 15:52:07 -0400)

are available in the git repository at:

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

for you to fetch changes up to b855d416dc17061ebb271ea7ef1201d100531770:

  netfilter: nf_tables: fix nft_cmp_fast failure on big endian for size < 4 (2014-04-14 10:38:02 +0200)

----------------------------------------------------------------
Andrey Vagin (2):
      netfilter: nf_conntrack: flush net_gre->keymap_list only from gre helper
      netfilter: nf_conntrack: initialize net.ct.generation

Patrick McHardy (1):
      netfilter: nf_tables: fix nft_cmp_fast failure on big endian for size < 4

 include/linux/netfilter/nf_conntrack_proto_gre.h |    1 -
 include/net/netfilter/nf_tables_core.h           |   10 ++++++++++
 net/netfilter/nf_conntrack_core.c                |    1 +
 net/netfilter/nf_conntrack_pptp.c                |   20 +-------------------
 net/netfilter/nf_conntrack_proto_gre.c           |    3 +--
 net/netfilter/nf_tables_core.c                   |    3 +--
 net/netfilter/nft_cmp.c                          |    2 +-
 7 files changed, 15 insertions(+), 25 deletions(-)

[PATCH 1/3] netfilter: nf_conntrack: flush net_gre->keymap_list only from gre helper

[Pablo Neira Ayuso]

From: Andrey Vagin <avagin@openvz.org>

nf_ct_gre_keymap_flush() removes a nf_ct_gre_keymap object from
net_gre->keymap_list and frees the object. But it doesn't clean
a reference on this object from ct_pptp_info->keymap[dir].
Then nf_ct_gre_keymap_destroy() may release the same object again.

So nf_ct_gre_keymap_flush() can be called only when we are sure that
when nf_ct_gre_keymap_destroy will not be called.

nf_ct_gre_keymap is created by nf_ct_gre_keymap_add() and the right way
to destroy it is to call nf_ct_gre_keymap_destroy().

This patch marks nf_ct_gre_keymap_flush() as static, so this patch can
break compilation of third party modules, which use
nf_ct_gre_keymap_flush. I'm not sure this is the right way to deprecate
this function.

[  226.540793] general protection fault: 0000 [#1] SMP
[  226.541750] Modules linked in: nf_nat_pptp nf_nat_proto_gre
nf_conntrack_pptp nf_conntrack_proto_gre ip_gre ip_tunnel gre
ppp_deflate bsd_comp ppp_async crc_ccitt ppp_generic slhc xt_nat
iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat
nf_conntrack veth tun bridge stp llc ppdev microcode joydev pcspkr
serio_raw virtio_console virtio_balloon floppy parport_pc parport
pvpanic i2c_piix4 virtio_net drm_kms_helper ttm ata_generic virtio_pci
virtio_ring virtio drm i2c_core pata_acpi [last unloaded: ip_tunnel]
[  226.541776] CPU: 0 PID: 49 Comm: kworker/u4:2 Not tainted 3.14.0-rc8+ #101
[  226.541776] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  226.541776] Workqueue: netns cleanup_net
[  226.541776] task: ffff8800371e0000 ti: ffff88003730c000 task.ti: ffff88003730c000
[  226.541776] RIP: 0010:[<ffffffff81389ba9>]  [<ffffffff81389ba9>] __list_del_entry+0x29/0xd0
[  226.541776] RSP: 0018:ffff88003730dbd0  EFLAGS: 00010a83
[  226.541776] RAX: 6b6b6b6b6b6b6b6b RBX: ffff8800374e6c40 RCX: dead000000200200
[  226.541776] RDX: 6b6b6b6b6b6b6b6b RSI: ffff8800371e07d0 RDI: ffff8800374e6c40
[  226.541776] RBP: ffff88003730dbd0 R08: 0000000000000000 R09: 0000000000000000
[  226.541776] R10: 0000000000000001 R11: ffff88003730d92e R12: 0000000000000002
[  226.541776] R13: ffff88007a4c42d0 R14: ffff88007aef0000 R15: ffff880036cf0018
[  226.541776] FS:  0000000000000000(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
[  226.541776] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  226.541776] CR2: 00007f07f643f7d0 CR3: 0000000036fd2000 CR4: 00000000000006f0
[  226.541776] Stack:
[  226.541776]  ffff88003730dbe8 ffffffff81389c5d ffff8800374ffbe4 ffff88003730dc28
[  226.541776]  ffffffffa0162a43 ffffffffa01627c5 ffff88007a4c42d0 ffff88007aef0000
[  226.541776]  ffffffffa01651c0 ffff88007a4c45e0 ffff88007aef0000 ffff88003730dc40
[  226.541776] Call Trace:
[  226.541776]  [<ffffffff81389c5d>] list_del+0xd/0x30
[  226.541776]  [<ffffffffa0162a43>] nf_ct_gre_keymap_destroy+0x283/0x2d0 [nf_conntrack_proto_gre]
[  226.541776]  [<ffffffffa01627c5>] ? nf_ct_gre_keymap_destroy+0x5/0x2d0 [nf_conntrack_proto_gre]
[  226.541776]  [<ffffffffa0162ab7>] gre_destroy+0x27/0x70 [nf_conntrack_proto_gre]
[  226.541776]  [<ffffffffa0117de3>] destroy_conntrack+0x83/0x200 [nf_conntrack]
[  226.541776]  [<ffffffffa0117d87>] ? destroy_conntrack+0x27/0x200 [nf_conntrack]
[  226.541776]  [<ffffffffa0117d60>] ? nf_conntrack_hash_check_insert+0x2e0/0x2e0 [nf_conntrack]
[  226.541776]  [<ffffffff81630142>] nf_conntrack_destroy+0x72/0x180
[  226.541776]  [<ffffffff816300d5>] ? nf_conntrack_destroy+0x5/0x180
[  226.541776]  [<ffffffffa011ef80>] ? kill_l3proto+0x20/0x20 [nf_conntrack]
[  226.541776]  [<ffffffffa011847e>] nf_ct_iterate_cleanup+0x14e/0x170 [nf_conntrack]
[  226.541776]  [<ffffffffa011f74b>] nf_ct_l4proto_pernet_unregister+0x5b/0x90 [nf_conntrack]
[  226.541776]  [<ffffffffa0162409>] proto_gre_net_exit+0x19/0x30 [nf_conntrack_proto_gre]
[  226.541776]  [<ffffffff815edf89>] ops_exit_list.isra.1+0x39/0x60
[  226.541776]  [<ffffffff815eecc0>] cleanup_net+0x100/0x1d0
[  226.541776]  [<ffffffff810a608a>] process_one_work+0x1ea/0x4f0
[  226.541776]  [<ffffffff810a6028>] ? process_one_work+0x188/0x4f0
[  226.541776]  [<ffffffff810a64ab>] worker_thread+0x11b/0x3a0
[  226.541776]  [<ffffffff810a6390>] ? process_one_work+0x4f0/0x4f0
[  226.541776]  [<ffffffff810af42d>] kthread+0xed/0x110
[  226.541776]  [<ffffffff8173d4dc>] ? _raw_spin_unlock_irq+0x2c/0x40
[  226.541776]  [<ffffffff810af340>] ? kthread_create_on_node+0x200/0x200
[  226.541776]  [<ffffffff8174747c>] ret_from_fork+0x7c/0xb0
[  226.541776]  [<ffffffff810af340>] ? kthread_create_on_node+0x200/0x200
[  226.541776] Code: 00 00 55 48 8b 17 48 b9 00 01 10 00 00 00 ad de
48 8b 47 08 48 89 e5 48 39 ca 74 29 48 b9 00 02 20 00 00 00 ad de 48
39 c8 74 7a <4c> 8b 00 4c 39 c7 75 53 4c 8b 42 08 4c 39 c7 75 2b 48 89
42 08
[  226.541776] RIP  [<ffffffff81389ba9>] __list_del_entry+0x29/0xd0
[  226.541776]  RSP <ffff88003730dbd0>
[  226.612193] ---[ end trace 985ae23ddfcc357c ]---

Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/linux/netfilter/nf_conntrack_proto_gre.h |    1 -
 net/netfilter/nf_conntrack_pptp.c                |   20 +-------------------
 net/netfilter/nf_conntrack_proto_gre.c           |    3 +--
 3 files changed, 2 insertions(+), 22 deletions(-)

diff --git a/include/linux/netfilter/nf_conntrack_proto_gre.h b/include/linux/netfilter/nf_conntrack_proto_gre.h
index ec2ffaf..df78dc2 100644
--- a/include/linux/netfilter/nf_conntrack_proto_gre.h
+++ b/include/linux/netfilter/nf_conntrack_proto_gre.h
@@ -87,7 +87,6 @@ int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
 /* delete keymap entries */
 void nf_ct_gre_keymap_destroy(struct nf_conn *ct);
 
-void nf_ct_gre_keymap_flush(struct net *net);
 void nf_nat_need_gre(void);
 
 #endif /* __KERNEL__ */
diff --git a/net/netfilter/nf_conntrack_pptp.c b/net/netfilter/nf_conntrack_pptp.c
index 7bd03de..825c3e3 100644
--- a/net/netfilter/nf_conntrack_pptp.c
+++ b/net/netfilter/nf_conntrack_pptp.c
@@ -605,32 +605,14 @@ static struct nf_conntrack_helper pptp __read_mostly = {
 	.expect_policy		= &pptp_exp_policy,
 };
 
-static void nf_conntrack_pptp_net_exit(struct net *net)
-{
-	nf_ct_gre_keymap_flush(net);
-}
-
-static struct pernet_operations nf_conntrack_pptp_net_ops = {
-	.exit = nf_conntrack_pptp_net_exit,
-};
-
 static int __init nf_conntrack_pptp_init(void)
 {
-	int rv;
-
-	rv = nf_conntrack_helper_register(&pptp);
-	if (rv < 0)
-		return rv;
-	rv = register_pernet_subsys(&nf_conntrack_pptp_net_ops);
-	if (rv < 0)
-		nf_conntrack_helper_unregister(&pptp);
-	return rv;
+	return nf_conntrack_helper_register(&pptp);
 }
 
 static void __exit nf_conntrack_pptp_fini(void)
 {
 	nf_conntrack_helper_unregister(&pptp);
-	unregister_pernet_subsys(&nf_conntrack_pptp_net_ops);
 }
 
 module_init(nf_conntrack_pptp_init);
diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c
index 9d9c0da..d566573 100644
--- a/net/netfilter/nf_conntrack_proto_gre.c
+++ b/net/netfilter/nf_conntrack_proto_gre.c
@@ -66,7 +66,7 @@ static inline struct netns_proto_gre *gre_pernet(struct net *net)
 	return net_generic(net, proto_gre_net_id);
 }
 
-void nf_ct_gre_keymap_flush(struct net *net)
+static void nf_ct_gre_keymap_flush(struct net *net)
 {
 	struct netns_proto_gre *net_gre = gre_pernet(net);
 	struct nf_ct_gre_keymap *km, *tmp;
@@ -78,7 +78,6 @@ void nf_ct_gre_keymap_flush(struct net *net)
 	}
 	write_unlock_bh(&net_gre->keymap_lock);
 }
-EXPORT_SYMBOL(nf_ct_gre_keymap_flush);
 
 static inline int gre_key_cmpfn(const struct nf_ct_gre_keymap *km,
 				const struct nf_conntrack_tuple *t)
-- 
1.7.10.4

[PATCH 2/3] netfilter: nf_conntrack: initialize net.ct.generation

[Pablo Neira Ayuso]

From: Andrey Vagin <avagin@openvz.org>

[  251.920788] INFO: trying to register non-static key.
[  251.921386] the code is fine but needs lockdep annotation.
[  251.921386] turning off the locking correctness validator.
[  251.921386] CPU: 2 PID: 15715 Comm: socket_listen Not tainted 3.14.0+ #294
[  251.921386] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  251.921386]  0000000000000000 000000009d18c210 ffff880075f039b8 ffffffff816b7ecd
[  251.921386]  ffffffff822c3b10 ffff880075f039c8 ffffffff816b36f4 ffff880075f03aa0
[  251.921386]  ffffffff810c65ff ffffffff810c4a85 00000000fffffe01 ffffffffa0075172
[  251.921386] Call Trace:
[  251.921386]  [<ffffffff816b7ecd>] dump_stack+0x45/0x56
[  251.921386]  [<ffffffff816b36f4>] register_lock_class.part.24+0x38/0x3c
[  251.921386]  [<ffffffff810c65ff>] __lock_acquire+0x168f/0x1b40
[  251.921386]  [<ffffffff810c4a85>] ? trace_hardirqs_on_caller+0x105/0x1d0
[  251.921386]  [<ffffffffa0075172>] ? nf_nat_setup_info+0x252/0x3a0 [nf_nat]
[  251.921386]  [<ffffffff816c1215>] ? _raw_spin_unlock_bh+0x35/0x40
[  251.921386]  [<ffffffffa0075172>] ? nf_nat_setup_info+0x252/0x3a0 [nf_nat]
[  251.921386]  [<ffffffff810c7272>] lock_acquire+0xa2/0x120
[  251.921386]  [<ffffffffa008ab90>] ? ipv4_confirm+0x90/0xf0 [nf_conntrack_ipv4]
[  251.921386]  [<ffffffffa0055989>] __nf_conntrack_confirm+0x129/0x410 [nf_conntrack]
[  251.921386]  [<ffffffffa008ab90>] ? ipv4_confirm+0x90/0xf0 [nf_conntrack_ipv4]
[  251.921386]  [<ffffffffa008ab90>] ipv4_confirm+0x90/0xf0 [nf_conntrack_ipv4]
[  251.921386]  [<ffffffff815e7b00>] ? ip_fragment+0x9f0/0x9f0
[  251.921386]  [<ffffffff815d8c5a>] nf_iterate+0xaa/0xc0
[  251.921386]  [<ffffffff815e7b00>] ? ip_fragment+0x9f0/0x9f0
[  251.921386]  [<ffffffff815d8d14>] nf_hook_slow+0xa4/0x190
[  251.921386]  [<ffffffff815e7b00>] ? ip_fragment+0x9f0/0x9f0
[  251.921386]  [<ffffffff815e98f2>] ip_output+0x92/0x100
[  251.921386]  [<ffffffff815e8df9>] ip_local_out+0x29/0x90
[  251.921386]  [<ffffffff815e9240>] ip_queue_xmit+0x170/0x4c0
[  251.921386]  [<ffffffff815e90d5>] ? ip_queue_xmit+0x5/0x4c0
[  251.921386]  [<ffffffff81601208>] tcp_transmit_skb+0x498/0x960
[  251.921386]  [<ffffffff81602d82>] tcp_connect+0x812/0x960
[  251.921386]  [<ffffffff810e3dc5>] ? ktime_get_real+0x25/0x70
[  251.921386]  [<ffffffff8159ea2a>] ? secure_tcp_sequence_number+0x6a/0xc0
[  251.921386]  [<ffffffff81606f57>] tcp_v4_connect+0x317/0x470
[  251.921386]  [<ffffffff8161f645>] __inet_stream_connect+0xb5/0x330
[  251.921386]  [<ffffffff8158dfc3>] ? lock_sock_nested+0x33/0xa0
[  251.921386]  [<ffffffff810c4b5d>] ? trace_hardirqs_on+0xd/0x10
[  251.921386]  [<ffffffff81078885>] ? __local_bh_enable_ip+0x75/0xe0
[  251.921386]  [<ffffffff8161f8f8>] inet_stream_connect+0x38/0x50
[  251.921386]  [<ffffffff8158b157>] SYSC_connect+0xe7/0x120
[  251.921386]  [<ffffffff810e3789>] ? current_kernel_time+0x69/0xd0
[  251.921386]  [<ffffffff810c4a85>] ? trace_hardirqs_on_caller+0x105/0x1d0
[  251.921386]  [<ffffffff810c4b5d>] ? trace_hardirqs_on+0xd/0x10
[  251.921386]  [<ffffffff8158c36e>] SyS_connect+0xe/0x10
[  251.921386]  [<ffffffff816caf69>] system_call_fastpath+0x16/0x1b
[  312.014104] INFO: rcu_sched detected stalls on CPUs/tasks: {} (detected by 0, t=60003 jiffies, g=42359, c=42358, q=333)
[  312.015097] INFO: Stall ended before state dump start

Fixes: 93bb0ceb75be ("netfilter: conntrack: remove central spinlock nf_conntrack_lock")
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conntrack_core.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 6dba48e..75421f2 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1795,6 +1795,7 @@ int nf_conntrack_init_net(struct net *net)
 	int cpu;
 
 	atomic_set(&net->ct.count, 0);
+	seqcount_init(&net->ct.generation);
 
 	net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
 	if (!net->ct.pcpu_lists)
-- 
1.7.10.4

[PATCH 3/3] netfilter: nf_tables: fix nft_cmp_fast failure on big endian for size < 4

[Pablo Neira Ayuso]

From: Patrick McHardy <kaber@trash.net>

nft_cmp_fast is used for equality comparisions of size <= 4. For
comparisions of size < 4 byte a mask is calculated that is applied to
both the data from userspace (during initialization) and the register
value (during runtime). Both values are stored using (in effect) memcpy
to a memory area that is then interpreted as u32 by nft_cmp_fast.

This works fine on little endian since smaller types have the same base
address, however on big endian this is not true and the smaller types
are interpreted as a big number with trailing zero bytes.

The mask therefore must not include the lower bytes, but the higher bytes
on big endian. Add a helper function that does a cpu_to_le32 to switch
the bytes on big endian. Since we're dealing with a mask of just consequitive
bits, this works out fine.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/netfilter/nf_tables_core.h |   10 ++++++++++
 net/netfilter/nf_tables_core.c         |    3 +--
 net/netfilter/nft_cmp.c                |    2 +-
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/include/net/netfilter/nf_tables_core.h b/include/net/netfilter/nf_tables_core.h
index cf2b7ae..a75fc8e 100644
--- a/include/net/netfilter/nf_tables_core.h
+++ b/include/net/netfilter/nf_tables_core.h
@@ -13,6 +13,16 @@ struct nft_cmp_fast_expr {
 	u8			len;
 };
 
+/* Calculate the mask for the nft_cmp_fast expression. On big endian the
+ * mask needs to include the *upper* bytes when interpreting that data as
+ * something smaller than the full u32, therefore a cpu_to_le32 is done.
+ */
+static inline u32 nft_cmp_fast_mask(unsigned int len)
+{
+	return cpu_to_le32(~0U >> (FIELD_SIZEOF(struct nft_cmp_fast_expr,
+						data) * BITS_PER_BYTE - len));
+}
+
 extern const struct nft_expr_ops nft_cmp_fast_ops;
 
 int nft_cmp_module_init(void);
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index 90998a6..8041053 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -25,9 +25,8 @@ static void nft_cmp_fast_eval(const struct nft_expr *expr,
 			      struct nft_data data[NFT_REG_MAX + 1])
 {
 	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
-	u32 mask;
+	u32 mask = nft_cmp_fast_mask(priv->len);
 
-	mask = ~0U >> (sizeof(priv->data) * BITS_PER_BYTE - priv->len);
 	if ((data[priv->sreg].data[0] & mask) == priv->data)
 		return;
 	data[NFT_REG_VERDICT].verdict = NFT_BREAK;
diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c
index 954925d..e2b3f51 100644
--- a/net/netfilter/nft_cmp.c
+++ b/net/netfilter/nft_cmp.c
@@ -128,7 +128,7 @@ static int nft_cmp_fast_init(const struct nft_ctx *ctx,
 	BUG_ON(err < 0);
 	desc.len *= BITS_PER_BYTE;
 
-	mask = ~0U >> (sizeof(priv->data) * BITS_PER_BYTE - desc.len);
+	mask = nft_cmp_fast_mask(desc.len);
 	priv->data = data.data[0] & mask;
 	priv->len  = desc.len;
 	return 0;
-- 
1.7.10.4

Re: [PATCH 0/3] Netfilter fixes for net

[David Miller]

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Tue, 15 Apr 2014 00:43:32 +0200

> The following patchset contains three Netfilter fixes for your net tree,
> they are:
> 
> * Fix missing generation sequence initialization which results in a splat
>   if lockdep is enabled, it was introduced in the recent works to improve
>   nf_conntrack scalability, from Andrey Vagin.
> 
> * Don't flush the GRE keymap list in nf_conntrack when the pptp helper is
>   disabled otherwise this crashes due to a double release, from Andrey
>   Vagin.
> 
> * Fix nf_tables cmp fast in big endian, from Patrick McHardy.

Pulled, thanks a lot Pablo.