On Fri, 2019-05-31 at 16:29 +0800, Young Xiao wrote:
> There is a possible null pointer deference bugs in neigh_fill_info(),
> which is similar to the bug which was fixed in commit 6adc5fd6a142
> ("net/neighbour: fix crash at dumping device-agnostic proxy entries").
>
> Signed-off-by: Young Xiao <92siuy...@gmail.com>
> ---
> net/core/neighbour.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/core/neighbour.c b/net/core/neighbour.c
> index dfa8710..33c3ff1 100644
> --- a/net/core/neighbour.c
> +++ b/net/core/neighbour.c
> @@ -2440,7 +2440,7 @@ static int neigh_fill_info(struct sk_buff *skb, struct
> neighbour *neigh,
> ndm->ndm_pad2 = 0;
> ndm->ndm_flags = neigh->flags;
> ndm->ndm_type = neigh->type;
> - ndm->ndm_ifindex = neigh->dev->ifindex;
> + ndm->ndm_ifindex = neigh->dev ? neigh->dev->ifindex : 0;
>
> if (nla_put(skb, NDA_DST, neigh->tbl->key_len, neigh->primary_key))
> goto nla_put_failure;
AFAICS, neigh->dev is requested to be != NULL at neighbour creation
time (see ___neigh_create()), so the above NULL ptr dereference looks
impossible. Am I missing something?
Thanks,
Paolo
