Re: [PATCH bpf] bpf: Fix integer overflow in queue_stack_map_alloc.

[Greg KH <greg@kroah.com>]

On Thu, Nov 22, 2018 at 11:59:02PM +0800, Wei Wu wrote:
> Integer overflow in queue_stack_map_alloc when calculating size may
> lead to heap overflow of arbitrary length.
> The patch fix it by checking whether attr->max_entries+1 <
> attr->max_entries and bailing out if it is the case.
> The vulnerability is discovered with the assistance of syzkaller.
> 
> Reported-by: Wei Wu <ww9210@gmail.com>
> To: Alexei Starovoitov <ast@kernel.org>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: netdev <netdev@vger.kernel.org>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Greg KH <greg@kroah.com>
> Signed-off-by: Wei Wu <ww9210@gmail.com>
> ---
>  kernel/bpf/queue_stack_maps.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c
> index 8bbd72d3a121..c35a8a4721c8 100644
> --- a/kernel/bpf/queue_stack_maps.c
> +++ b/kernel/bpf/queue_stack_maps.c
> @@ -67,6 +67,8 @@ static struct bpf_map *queue_stack_map_alloc(union
> bpf_attr *attr)
>   u64 queue_size, cost;
> 
>   size = attr->max_entries + 1;
> + if (size < attr->max_entries)
> + return ERR_PTR(-EINVAL);
>   value_size = attr->value_size;

Your tabs got eaten by your email client and they all disappeared,
making the patch impossible to apply :(

Care to try again?

thanks,

greg k-h