[PATCH 1/1] net: don't memcpy to NULL

[Vyacheslav Mitrofanov V]

On Wed, 2022-12-07 at 11:53 +0100, Heinrich Schuchardt wrote:
> «Внимание! Данное письмо от внешнего адресата!»
> 
> In ndisc_receive() 7 bytes are copied from a buffer of size 6 to
> NULL.
> 
> net_nd_packet_mac is a pointer. If it is NULL, we should set it to
> the
> address of the buffer with the MAC address.
> 
> Addresses-Coverity-ID: 430974 ("Out-of-bounds access")
> Fixes: c6610e1d90ea ("net: ipv6: Add Neighbor Discovery Protocol
> (NDP)")
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com
> >
> ---
>  net/ndisc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/ndisc.c b/net/ndisc.c
> index 3c0eeeaea3..367dae7676 100644
> --- a/net/ndisc.c
> +++ b/net/ndisc.c
> @@ -265,7 +265,7 @@ int ndisc_receive(struct ethernet_hdr *et, struct
> ip6_hdr *ip6, int len)
> 
>                         /* save address for later use */
>                         if (!net_nd_packet_mac)
> -                               memcpy(net_nd_packet_mac,
> neigh_eth_addr, 7);
> +                               net_nd_packet_mac = neigh_eth_addr;
> 
>                         /* modify header, and transmit it */
>                         memcpy(((struct ethernet_hdr
> *)net_nd_tx_packet)->et_dest,
> --
> 2.37.2
> 
> 
Reviewed-by: Viacheslav Mitrofanov <v.v.mitrofanov at yadro.com>