ipvs 02/04: Add boundary check on ioctl arguments

[Patrick McHardy <kaber@trash.net>]

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))