[ACKED] [PATCH 3/6] netfilter: ip_tables: fix infoleak to userspace CVE-2011-1171

Andy Whitcroft apw at canonical.com
Mon Jul 4 17:01:35 UTC 2011


On Mon, Jul 04, 2011 at 05:22:43PM +0100, paolo.pisati at canonical.com wrote:
> From: Vasiliy Kulikov <segoon at openwall.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/801482
> 
> commit upstream 78b79876761b86653df89c48a7010b5cbd41a84a
> 
> Structures ipt_replace, compat_ipt_replace, and xt_get_revision are
> copied from userspace.  Fields of these structs that are
> zero-terminated strings are not checked.  When they are used as argument
> to a format string containing "%s" in request_module(), some sensitive
> information is leaked to userspace via argument of spawned modprobe
> process.
> 
> The first and the third bugs were introduced before the git epoch; the
> second was introduced in 2722971c (v2.6.17-rc1).  To trigger the bug
> one should have CAP_NET_ADMIN.
> 
> CVE-2011-1171
> 
> Signed-off-by: Vasiliy Kulikov <segoon at openwall.com>
> Signed-off-by: Patrick McHardy <kaber at trash.net>
> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>
> ---
>  net/ipv4/netfilter/ip_tables.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
> index b9b189c..9b52e88 100644
> --- a/net/ipv4/netfilter/ip_tables.c
> +++ b/net/ipv4/netfilter/ip_tables.c
> @@ -1332,6 +1332,7 @@ do_replace(void __user *user, unsigned int len)
>  		return -ENOMEM;
>  	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
>  		return -ENOMEM;
> +	tmp.name[sizeof(tmp.name)-1] = 0;
>  
>  	newinfo = xt_alloc_table_info(tmp.size);
>  	if (!newinfo)
> @@ -1873,6 +1874,7 @@ compat_do_replace(void __user *user, unsigned int len)
>  		return -ENOMEM;
>  	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
>  		return -ENOMEM;
> +	tmp.name[sizeof(tmp.name)-1] = 0;
>  
>  	newinfo = xt_alloc_table_info(tmp.size);
>  	if (!newinfo)
> @@ -2101,6 +2103,7 @@ do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
>  			ret = -EFAULT;
>  			break;
>  		}
> +		rev.name[sizeof(rev.name)-1] = 0;
>  
>  		if (cmd == IPT_SO_GET_REVISION_TARGET)
>  			target = 1;

Appears identicle to upstream commit, also appears sane.

Acked-by: Andy Whitcroft <apw at canonical.com>

-apw




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