netfilter 00/04: netfilter fixes

netfilter 00/04: netfilter fixes

[Patrick McHardy]

Hi Dave,

the following patches fix a couple of bugs in netfilter and IPVS:

- use lib/gcd in IPVS

- add missing boundary checks for IPVS ioctl arguments, from Arjan

- fix an out-of-bounds read in FTP conntrack, from myself

- add missing CAP_NET_ADMIN check to ebtables, from Florian Westphal.
  ebtables userspace uses IP RAW sockets to address ebtables, which
  enforce CAP_NET_RAW. Any other IP socket type allows unpriviledged
  access to the ebtables ruleset.

Please apply or pull from:

git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-2.6.git master

Thanks!


 net/bridge/netfilter/ebtables.c  |    6 ++++++
 net/netfilter/ipvs/Kconfig       |    3 ++-
 net/netfilter/ipvs/ip_vs_ctl.c   |   14 +++++++++++++-
 net/netfilter/ipvs/ip_vs_wrr.c   |   15 +--------------
 net/netfilter/nf_conntrack_ftp.c |   18 +++++++++---------
 5 files changed, 31 insertions(+), 25 deletions(-)

Arjan van de Ven (1):
      ipvs: Add boundary check on ioctl arguments

Florian Fainelli (1):
      ipvs: ip_vs_wrr.c: use lib/gcd.c

Florian Westphal (1):
      netfilter: ebtables: enforce CAP_NET_ADMIN

Patrick McHardy (1):
      netfilter: nf_ct_ftp: fix out of bounds read in update_nl_seq()

ipvs 01/04: ip_vs_wrr.c: use lib/gcd.c

[Patrick McHardy]

commit ae24e578de02b87cce3dc59248c29b2ecb071e9e
Author: Florian Fainelli <florian@openwrt.org>
Date:   Tue Dec 22 09:42:06 2009 +0100

    ipvs: ip_vs_wrr.c: use lib/gcd.c
    
    Remove the private version of the greatest common divider to use
    lib/gcd.c, the latter also implementing the a < b case.
    
    [akpm@linux-foundation.org: repair neighboring whitespace because the diff looked odd]
    Signed-off-by: Florian Fainelli <florian@openwrt.org>
    Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
    Cc: Takashi Iwai <tiwai@suse.de>
    Acked-by: Simon Horman <horms@verge.net.au>
    Cc: Julius Volz <juliusv@google.com>
    Cc: David S. Miller <davem@davemloft.net>
    Cc: Patrick McHardy <kaber@trash.net>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/net/netfilter/ipvs/Kconfig b/net/netfilter/ipvs/Kconfig
index 79a6980..f2d7623 100644
--- a/net/netfilter/ipvs/Kconfig
+++ b/net/netfilter/ipvs/Kconfig
@@ -112,7 +112,8 @@ config	IP_VS_RR
 	  module, choose M here. If unsure, say N.
  
 config	IP_VS_WRR
-        tristate "weighted round-robin scheduling" 
+	tristate "weighted round-robin scheduling"
+	select GCD
 	---help---
 	  The weighted robin-robin scheduling algorithm directs network
 	  connections to different real servers based on server weights
diff --git a/net/netfilter/ipvs/ip_vs_wrr.c b/net/netfilter/ipvs/ip_vs_wrr.c
index 6182e8e..3c115fc 100644
--- a/net/netfilter/ipvs/ip_vs_wrr.c
+++ b/net/netfilter/ipvs/ip_vs_wrr.c
@@ -24,6 +24,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/net.h>
+#include <linux/gcd.h>
 
 #include <net/ip_vs.h>
 
@@ -38,20 +39,6 @@ struct ip_vs_wrr_mark {
 };
 
 
-/*
- *    Get the gcd of server weights
- */
-static int gcd(int a, int b)
-{
-	int c;
-
-	while ((c = a % b)) {
-		a = b;
-		b = c;
-	}
-	return b;
-}
-
 static int ip_vs_wrr_gcd_weight(struct ip_vs_service *svc)
 {
 	struct ip_vs_dest *dest;

ipvs 02/04: Add boundary check on ioctl arguments

[Patrick McHardy]

commit 04bcef2a83f40c6db24222b27a52892cba39dffb
Author: Arjan van de Ven <arjan@linux.intel.com>
Date:   Mon Jan 4 16:37:12 2010 +0100

    ipvs: Add boundary check on ioctl arguments
    
    The ipvs code has a nifty system for doing the size of ioctl command
    copies; it defines an array with values into which it indexes the cmd
    to find the right length.
    
    Unfortunately, the ipvs code forgot to check if the cmd was in the
    range that the array provides, allowing for an index outside of the
    array, which then gives a "garbage" result into the length, which
    then gets used for copying into a stack buffer.
    
    Fix this by adding sanity checks on these as well as the copy size.
    
    [ horms@verge.net.au: adjusted limit to IP_VS_SO_GET_MAX ]
    Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
    Acked-by: Julian Anastasov <ja@ssi.bg>
    Signed-off-by: Simon Horman <horms@verge.net.au>
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 6bde12d..c37ac2d 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -2077,6 +2077,10 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 
+	if (cmd < IP_VS_BASE_CTL || cmd > IP_VS_SO_SET_MAX)
+		return -EINVAL;
+	if (len < 0 || len >  MAX_ARG_LEN)
+		return -EINVAL;
 	if (len != set_arglen[SET_CMDID(cmd)]) {
 		pr_err("set_ctl: len %u != %u\n",
 		       len, set_arglen[SET_CMDID(cmd)]);
@@ -2352,17 +2356,25 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
 {
 	unsigned char arg[128];
 	int ret = 0;
+	unsigned int copylen;
 
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 
+	if (cmd < IP_VS_BASE_CTL || cmd > IP_VS_SO_GET_MAX)
+		return -EINVAL;
+
 	if (*len < get_arglen[GET_CMDID(cmd)]) {
 		pr_err("get_ctl: len %u < %u\n",
 		       *len, get_arglen[GET_CMDID(cmd)]);
 		return -EINVAL;
 	}
 
-	if (copy_from_user(arg, user, get_arglen[GET_CMDID(cmd)]) != 0)
+	copylen = get_arglen[GET_CMDID(cmd)];
+	if (copylen > 128)
+		return -EINVAL;
+
+	if (copy_from_user(arg, user, copylen) != 0)
 		return -EFAULT;
 
 	if (mutex_lock_interruptible(&__ip_vs_mutex))

netfilter 03/04: nf_ct_ftp: fix out of bounds read in update_nl_seq()

[Patrick McHardy]

commit aaff23a95aea5f000895f50d90e91f1e2f727002
Author: Patrick McHardy <kaber@trash.net>
Date:   Thu Jan 7 18:33:18 2010 +0100

    netfilter: nf_ct_ftp: fix out of bounds read in update_nl_seq()
    
    As noticed by Dan Carpenter <error27@gmail.com>, update_nl_seq()
    currently contains an out of bounds read of the seq_aft_nl array
    when looking for the oldest sequence number position.
    
    Fix it to only compare valid positions.
    
    Cc: stable@kernel.org
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 38ea7ef..f0732aa 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -323,24 +323,24 @@ static void update_nl_seq(struct nf_conn *ct, u32 nl_seq,
 			  struct nf_ct_ftp_master *info, int dir,
 			  struct sk_buff *skb)
 {
-	unsigned int i, oldest = NUM_SEQ_TO_REMEMBER;
+	unsigned int i, oldest;
 
 	/* Look for oldest: if we find exact match, we're done. */
 	for (i = 0; i < info->seq_aft_nl_num[dir]; i++) {
 		if (info->seq_aft_nl[dir][i] == nl_seq)
 			return;
-
-		if (oldest == info->seq_aft_nl_num[dir] ||
-		    before(info->seq_aft_nl[dir][i],
-			   info->seq_aft_nl[dir][oldest]))
-			oldest = i;
 	}
 
 	if (info->seq_aft_nl_num[dir] < NUM_SEQ_TO_REMEMBER) {
 		info->seq_aft_nl[dir][info->seq_aft_nl_num[dir]++] = nl_seq;
-	} else if (oldest != NUM_SEQ_TO_REMEMBER &&
-		   after(nl_seq, info->seq_aft_nl[dir][oldest])) {
-		info->seq_aft_nl[dir][oldest] = nl_seq;
+	} else {
+		if (before(info->seq_aft_nl[dir][0], info->seq_aft_nl[dir][1]))
+			oldest = 0;
+		else
+			oldest = 1;
+
+		if (after(nl_seq, info->seq_aft_nl[dir][oldest]))
+			info->seq_aft_nl[dir][oldest] = nl_seq;
 	}
 }
 

netfilter 04/04: ebtables: enforce CAP_NET_ADMIN

[Patrick McHardy]

commit dce766af541f6605fa9889892c0280bab31c66ab
Author: Florian Westphal <fwestphal@astaro.com>
Date:   Fri Jan 8 17:31:24 2010 +0100

    netfilter: ebtables: enforce CAP_NET_ADMIN
    
    normal users are currently allowed to set/modify ebtables rules.
    Restrict it to processes with CAP_NET_ADMIN.
    
    Note that this cannot be reproduced with unmodified ebtables binary
    because it uses SOCK_RAW.
    
    Signed-off-by: Florian Westphal <fwestphal@astaro.com>
    Cc: stable@kernel.org
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index bd1c654..0b7f262 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1406,6 +1406,9 @@ static int do_ebt_set_ctl(struct sock *sk,
 {
 	int ret;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	switch(cmd) {
 	case EBT_SO_SET_ENTRIES:
 		ret = do_replace(sock_net(sk), user, len);
@@ -1425,6 +1428,9 @@ static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
 	struct ebt_replace tmp;
 	struct ebt_table *t;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (copy_from_user(&tmp, user, sizeof(tmp)))
 		return -EFAULT;
 

Re: netfilter 00/04: netfilter fixes

[David Miller]

From: Patrick McHardy <kaber@trash.net>
Date: Fri,  8 Jan 2010 17:42:07 +0100 (MET)

> the following patches fix a couple of bugs in netfilter and IPVS:
> 
> - use lib/gcd in IPVS
> 
> - add missing boundary checks for IPVS ioctl arguments, from Arjan
> 
> - fix an out-of-bounds read in FTP conntrack, from myself
> 
> - add missing CAP_NET_ADMIN check to ebtables, from Florian Westphal.
>   ebtables userspace uses IP RAW sockets to address ebtables, which
>   enforce CAP_NET_RAW. Any other IP socket type allows unpriviledged
>   access to the ebtables ruleset.
> 
> Please apply or pull from:
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-2.6.git master

Pulled, thanks Patrick.