Patchwork [6/6] ipv6: netfilter: ip6_tables: fix infoleak to userspace CVE-2011-1172

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Submitter Paolo Pisati
Date July 4, 2011, 4:27 p.m.
Message ID <1309796858-2752-2-git-send-email-paolo.pisati@canonical.com>
Download mbox | patch
Permalink /patch/103138/
State New
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Comments

Paolo Pisati - July 4, 2011, 4:27 p.m.
From: Vasiliy Kulikov <segoon@openwall.com>

BugLink: http://bugs.launchpad.net/bugs/801483

commit upstream 6a8ab060779779de8aea92ce3337ca348f973f54

Structures ip6t_replace, compat_ip6t_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 bug was introduced before the git epoch;  the second was
introduced in 3bc3fe5e (v2.6.25-rc1);  the third is introduced by
6b7d31fc (v2.6.15-rc1).  To trigger the bug one should have
CAP_NET_ADMIN.

CVE-2011-1172

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
---
 net/ipv6/netfilter/ip6_tables.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
Andy Whitcroft - July 4, 2011, 5:06 p.m.
On Mon, Jul 04, 2011 at 05:27:38PM +0100, paolo.pisati@canonical.com wrote:
> From: Vasiliy Kulikov <segoon@openwall.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/801483
> 
> commit upstream 6a8ab060779779de8aea92ce3337ca348f973f54
> 
> Structures ip6t_replace, compat_ip6t_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 bug was introduced before the git epoch;  the second was
> introduced in 3bc3fe5e (v2.6.25-rc1);  the third is introduced by
> 6b7d31fc (v2.6.15-rc1).  To trigger the bug one should have
> CAP_NET_ADMIN.
> 
> CVE-2011-1172
> 
> Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
> Signed-off-by: Patrick McHardy <kaber@trash.net>
> Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
> ---
>  net/ipv6/netfilter/ip6_tables.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
> index acaba15..e02284a 100644
> --- a/net/ipv6/netfilter/ip6_tables.c
> +++ b/net/ipv6/netfilter/ip6_tables.c
> @@ -1047,6 +1047,7 @@ 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)
> @@ -1313,6 +1314,7 @@ do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
>  			ret = -EFAULT;
>  			break;
>  		}
> +		rev.name[sizeof(rev.name)-1] = 0;
>  
>  		if (cmd == IP6T_SO_GET_REVISION_TARGET)
>  			target = 1;

Misses one hunk which applies to non-existant code.  Looks sane.

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

-apw

Patch

diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index acaba15..e02284a 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1047,6 +1047,7 @@  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)
@@ -1313,6 +1314,7 @@  do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
 			ret = -EFAULT;
 			break;
 		}
+		rev.name[sizeof(rev.name)-1] = 0;
 
 		if (cmd == IP6T_SO_GET_REVISION_TARGET)
 			target = 1;