Re: [PATCH net-next] bpf: dev_map_alloc() shouldn't return NULL

John Fastabend
2017-07-22T19:07:09Z

On 07/22/2017 12:40 AM, Dan Carpenter wrote:
> We forgot to set the error code on two error paths which means that we
> return ERR_PTR(0) which is NULL. The caller, find_and_alloc_map(), is
> not expecting that and will have a NULL dereference.
>
> Fixes: 546ac1ffb70d ("bpf: add devmap, a map for storing net device references")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
> index 899364d097f5..d439ee0eadb1 100644
> --- a/kernel/bpf/devmap.c
> +++ b/kernel/bpf/devmap.c
> @@ -114,6 +114,7 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
> if (err)
> goto free_dtab;
>
> + err = -ENOMEM;
> /* A per cpu bitfield with a bit per possible net device */
> dtab->flush_needed = __alloc_percpu(
> BITS_TO_LONGS(attr->max_entries) *
>

Thanks.

Acked-by: John Fastabend <john.fastabend@gmail.com>