Skip to content
Browse files

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>
  • Loading branch information...
1 parent ae24e57 commit 04bcef2a83f40c6db24222b27a52892cba39dffb @fenrus75 fenrus75 committed with kaber
Showing with 13 additions and 1 deletion.
  1. +13 −1 net/netfilter/ipvs/ip_vs_ctl.c
View
14 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))

0 comments on commit 04bcef2

Please sign in to comment.
Something went wrong with that request. Please try again.