ipv6: netfilter: ip6_tables: fix infoleak to userspace CVE-2011-1172
 

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

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