On Thu, Mar 10, 2016 at 01:56:23AM +0100, Florian Westphal wrote:
> Ben Hawkes says:
> integer overflow in xt_alloc_table_info, which on 32-bit systems can
> lead to small structure allocation and a copy_from_user based heap
> corruption.
Applied, thanks Florian. I have slightly mangled this patch, the
second check suffices to catch this case for us.
> Reported-by: Ben Hawkes <hawkes@xxxxxxxxxx>
> Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
> ---
> net/netfilter/x_tables.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
> index c8a0b7d..17a9a9f 100644
> --- a/net/netfilter/x_tables.c
> +++ b/net/netfilter/x_tables.c
> @@ -659,6 +659,9 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size)
> struct xt_table_info *info = NULL;
> size_t sz = sizeof(*info) + size;
>
> + if (sz < size || sz < sizeof(*info))
> + return NULL;
So this will show up in the tree like this:
if (sz < sizeof(*info))
return NULL;
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
