[SLOF] [PATCH 4/5] ipv6: Fix NULL pointer dereference in ip6addr_add()

[Andrew Jones]

On Mon, May 02, 2016 at 09:55:30PM +0200, Thomas Huth wrote:
> When ip6addr_add() is called for the first time, both the first_ip6
> and the last_ip6 pointer are not initialized yet, i.e. contain NULL.
> So writing to "last_ip6->next" is a bad idea here. Fix it so that
> this value is only written when the function is not called for the
> first time.
> 
> Signed-off-by: Thomas Huth <thuth at redhat.com>
> ---
>  clients/net-snk/app/netlib/ipv6.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Andrew Jones <drjones at redhat.com>

> 
> diff --git a/clients/net-snk/app/netlib/ipv6.c b/clients/net-snk/app/netlib/ipv6.c
> index 220fd36..6aa1ea3 100644
> --- a/clients/net-snk/app/netlib/ipv6.c
> +++ b/clients/net-snk/app/netlib/ipv6.c
> @@ -330,7 +330,8 @@ int8_t ip6addr_add(struct ip6addr_list_entry *new_address)
>  
>  	if (first_ip6 == NULL)
>  		first_ip6 = new_address;
> -	last_ip6->next = new_address;
> +	else
> +		last_ip6->next = new_address;
>  	last_ip6 = new_address;
>  	last_ip6->next = NULL;
>  
> -- 
> 1.8.3.1
>