[NETFILTER 00/03]: Netfilter fixes

[NETFILTER 00/03]: Netfilter fixes

[Patrick McHardy]

Hi Dave,

these three patches fix (again) skb_over_panic caused by netfilter queueing,
a namespace leak when reading /proc/net/xxx_tables_names and incorrect error
handling in the TCPOPTSTRIP target.

Please apply, thanks.


 net/ipv4/netfilter/ip_queue.c   |    5 ++---
 net/ipv6/netfilter/ip6_queue.c  |    5 ++---
 net/netfilter/nfnetlink_queue.c |    5 ++---
 net/netfilter/x_tables.c        |    2 +-
 net/netfilter/xt_TCPOPTSTRIP.c  |    2 +-
 5 files changed, 8 insertions(+), 11 deletions(-)

Arnaud Ebalard (1):
      [NETFILTER]: {nfnetlink,ip,ip6}_queue: fix skb_over_panic when enlarging packets

Pavel Emelyanov (1):
      [NETFILTER]: x_tables: fix net namespace leak when reading /proc/net/xxx_tables_names

Roel Kluin (1):
      [NETFILTER]: xt_TCPOPTSTRIP: signed tcphoff for	ipv6_skip_exthdr() retval

[NETFILTER 01/03]: xt_TCPOPTSTRIP: signed tcphoff for ipv6_skip_exthdr() retval

[Patrick McHardy]

[NETFILTER]: xt_TCPOPTSTRIP: signed tcphoff for	ipv6_skip_exthdr() retval

if tcphoff remains unsigned, a negative ipv6_skip_exthdr() return value will
go unnoticed,

Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Signed-off-by: Patrick McHardy <kaber@trash.net>

---
commit 409c904821b52f9c4597ca87f3ab01b55183904e
tree 648fe90316d4c3d8e714ceefc9137325e8ef8417
parent 358c12953b88c5a06a57c33eb27c753b2e7934d1
author Roel Kluin <12o3l@tiscali.nl> Mon, 28 Apr 2008 20:58:54 +0200
committer Patrick McHardy <kaber@trash.net> Mon, 28 Apr 2008 20:58:54 +0200

 net/netfilter/xt_TCPOPTSTRIP.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/netfilter/xt_TCPOPTSTRIP.c b/net/netfilter/xt_TCPOPTSTRIP.c
index 3b2aa56..9685b6f 100644
--- a/net/netfilter/xt_TCPOPTSTRIP.c
+++ b/net/netfilter/xt_TCPOPTSTRIP.c
@@ -90,7 +90,7 @@ tcpoptstrip_tg6(struct sk_buff *skb, const struct net_device *in,
 		const struct xt_target *target, const void *targinfo)
 {
 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
-	unsigned int tcphoff;
+	int tcphoff;
 	u_int8_t nexthdr;
 
 	nexthdr = ipv6h->nexthdr;

[NETFILTER 02/03]: x_tables: fix net namespace leak when reading /proc/net/xxx_tables_names

[Patrick McHardy]

[NETFILTER]: x_tables: fix net namespace leak when reading /proc/net/xxx_tables_names

The seq_open_net() call should be accompanied with seq_release_net() one.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

---
commit 6317c53b124105c288604f51d50e2c759f6f333b
tree dc91473a4ea1688a27c71f3a0336bfcee922b6c5
parent 409c904821b52f9c4597ca87f3ab01b55183904e
author Pavel Emelyanov <xemul@openvz.org> Tue, 29 Apr 2008 00:02:17 +0200
committer Patrick McHardy <kaber@trash.net> Tue, 29 Apr 2008 00:02:17 +0200

 net/netfilter/x_tables.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index f52f7f8..11b22ab 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -787,7 +787,7 @@ static const struct file_operations xt_table_ops = {
 	.open	 = xt_table_open,
 	.read	 = seq_read,
 	.llseek	 = seq_lseek,
-	.release = seq_release,
+	.release = seq_release_net,
 };
 
 static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)

[NETFILTER 03/03]: {nfnetlink,ip,ip6}_queue: fix skb_over_panic when enlarging packets

[Patrick McHardy]

[NETFILTER]: {nfnetlink,ip,ip6}_queue: fix skb_over_panic when enlarging packets

While reinjecting *bigger* modified versions of IPv6 packets using
libnetfilter_queue, things work fine on a 2.6.24 kernel (2.6.22 too)
but I get the following on recents kernels (2.6.25, trace below is
against today's net-2.6 git tree):

skb_over_panic: text:c04fddb0 len:696 put:632 head:f7592c00 data:f7592c00 tail:0xf7592eb8 end:0xf7592e80 dev:eth0
------------[ cut here ]------------
invalid opcode: 0000 [#1] PREEMPT 
Process sendd (pid: 3657, ti=f6014000 task=f77c31d0 task.ti=f6014000)
Stack: c071e638 c04fddb0 000002b8 00000278 f7592c00 f7592c00 f7592eb8 f7592e80 
       f763c000 f6bc5200 f7592c40 f6015c34 c04cdbfc f6bc5200 00000278 f6015c60 
       c04fddb0 00000020 f72a10c0 f751b420 00000001 0000000a 000002b8 c065582c 
Call Trace:
 [<c04fddb0>] ? nfqnl_recv_verdict+0x1c0/0x2e0
 [<c04cdbfc>] ? skb_put+0x3c/0x40
 [<c04fddb0>] ? nfqnl_recv_verdict+0x1c0/0x2e0
 [<c04fd115>] ? nfnetlink_rcv_msg+0xf5/0x160
 [<c04fd03e>] ? nfnetlink_rcv_msg+0x1e/0x160
 [<c04fd020>] ? nfnetlink_rcv_msg+0x0/0x160
 [<c04f8ed7>] ? netlink_rcv_skb+0x77/0xa0
 [<c04fcefc>] ? nfnetlink_rcv+0x1c/0x30
 [<c04f8c73>] ? netlink_unicast+0x243/0x2b0
 [<c04cfaba>] ? memcpy_fromiovec+0x4a/0x70
 [<c04f9406>] ? netlink_sendmsg+0x1c6/0x270
 [<c04c8244>] ? sock_sendmsg+0xc4/0xf0
 [<c011970d>] ? set_next_entity+0x1d/0x50
 [<c0133a80>] ? autoremove_wake_function+0x0/0x40
 [<c0118f9e>] ? __wake_up_common+0x3e/0x70
 [<c0342fbf>] ? n_tty_receive_buf+0x34f/0x1280
 [<c011d308>] ? __wake_up+0x68/0x70
 [<c02cea47>] ? copy_from_user+0x37/0x70
 [<c04cfd7c>] ? verify_iovec+0x2c/0x90
 [<c04c837a>] ? sys_sendmsg+0x10a/0x230
 [<c011967a>] ? __dequeue_entity+0x2a/0xa0
 [<c011970d>] ? set_next_entity+0x1d/0x50
 [<c0345397>] ? pty_write+0x47/0x60
 [<c033d59b>] ? tty_default_put_char+0x1b/0x20
 [<c011d2e9>] ? __wake_up+0x49/0x70
 [<c033df99>] ? tty_ldisc_deref+0x39/0x90
 [<c033ff20>] ? tty_write+0x1a0/0x1b0
 [<c04c93af>] ? sys_socketcall+0x7f/0x260
 [<c0102ff9>] ? sysenter_past_esp+0x6a/0x91
 [<c05f0000>] ? snd_intel8x0m_probe+0x270/0x6e0
 =======================
Code: 00 00 89 5c 24 14 8b 98 9c 00 00 00 89 54 24 0c 89 5c 24 10 8b 40 50 89 4c 24 04 c7 04 24 38 e6 71 c0 89 44 24 08 e8 c4 46 c5 ff <0f> 0b eb fe 55 89 e5 56 89 d6 53 89 c3 83 ec 0c 8b 40 50 39 d0 
EIP: [<c04ccdfc>] skb_over_panic+0x5c/0x60 SS:ESP 0068:f6015bf8


Looking at the code, I ended up in nfq_mangle() function (called by
nfqnl_recv_verdict()) which performs a call to skb_copy_expand() due to
the increased size of data passed to the function. AFAICT, it should ask
for 'diff' instead of 'diff - skb_tailroom(e->skb)'. Because the
resulting sk_buff has not enough space to support the skb_put(skb, diff)
call a few lines later, this results in the call to skb_over_panic().

The patch below asks for allocation of a copy with enough space for
mangled packet and the same amount of headroom as old sk_buff. While
looking at how the regression appeared (e2b58a67), I noticed the same
pattern in ipq_mangle_ipv6() and ipq_mangle_ipv4(). The patch corrects
those locations too.

Tested with bigger reinjected IPv6 packets (nfqnl_mangle() path), things
are ok (2.6.25 and today's net-2.6 git tree).

Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

---
commit b8bd109c63a5d0d72530c7f59fc2412b03fa75ac
tree 4587cc797b38f3f133f7d198ecb6ffeadbaaaf97
parent 6317c53b124105c288604f51d50e2c759f6f333b
author Arnaud Ebalard <arno@natisbad.org> Tue, 29 Apr 2008 00:02:25 +0200
committer Patrick McHardy <kaber@trash.net> Tue, 29 Apr 2008 00:02:25 +0200

 net/ipv4/netfilter/ip_queue.c   |    5 ++---
 net/ipv6/netfilter/ip6_queue.c  |    5 ++---
 net/netfilter/nfnetlink_queue.c |    5 ++---
 3 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index 719be29..26a37ce 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -296,9 +296,8 @@ ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct nf_queue_entry *e)
 		if (v->data_len > 0xFFFF)
 			return -EINVAL;
 		if (diff > skb_tailroom(e->skb)) {
-			nskb = skb_copy_expand(e->skb, 0,
-					       diff - skb_tailroom(e->skb),
-					       GFP_ATOMIC);
+			nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
+					       diff, GFP_ATOMIC);
 			if (!nskb) {
 				printk(KERN_WARNING "ip_queue: error "
 				      "in mangle, dropping packet\n");
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index 92a36c9..2eff3ae 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -298,9 +298,8 @@ ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct nf_queue_entry *e)
 		if (v->data_len > 0xFFFF)
 			return -EINVAL;
 		if (diff > skb_tailroom(e->skb)) {
-			nskb = skb_copy_expand(e->skb, 0,
-					       diff - skb_tailroom(e->skb),
-					       GFP_ATOMIC);
+			nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
+					       diff, GFP_ATOMIC);
 			if (!nskb) {
 				printk(KERN_WARNING "ip6_queue: OOM "
 				      "in mangle, dropping packet\n");
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 2c9fe5c..3447025 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -454,9 +454,8 @@ nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e)
 		if (data_len > 0xFFFF)
 			return -EINVAL;
 		if (diff > skb_tailroom(e->skb)) {
-			nskb = skb_copy_expand(e->skb, 0,
-					       diff - skb_tailroom(e->skb),
-					       GFP_ATOMIC);
+			nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
+					       diff, GFP_ATOMIC);
 			if (!nskb) {
 				printk(KERN_WARNING "nf_queue: OOM "
 				      "in mangle, dropping packet\n");

Re: [NETFILTER 00/03]: Netfilter fixes

[David Miller]

From: Patrick McHardy <kaber@trash.net>
Date: Tue, 29 Apr 2008 00:06:40 +0200 (MEST)

> these three patches fix (again) skb_over_panic caused by netfilter queueing,
> a namespace leak when reading /proc/net/xxx_tables_names and incorrect error
> handling in the TCPOPTSTRIP target.
> 
> Please apply, thanks.

All 3 patches applied, thanks Patrick.