Re: [PATCH] net: Fix kernel-infoleak in __skb_datagram_iter (2)

[syzbot <syzbot+34ad5fab48f7bf510349@syzkaller.appspotmail.com>]

> #syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

want either no args or 2 args (repo, branch), got 1

> 9f8413c4a66f
>
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index 27998f73183e..c7bf1c38b292 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -2532,6 +2532,11 @@ static inline unsigned char
> *skb_tail_pointer(const struct sk_buff *skb)
>   return skb->head + skb->tail;
>  }
>
> +static inline unsigned int skb_tail_offset(const struct sk_buff *skb)
> +{
> + return skb->tail;
> +}
> +
>  static inline void skb_reset_tail_pointer(struct sk_buff *skb)
>  {
>   skb->tail = skb->data - skb->head;
> @@ -2549,6 +2554,11 @@ static inline unsigned char
> *skb_tail_pointer(const struct sk_buff *skb)
>   return skb->tail;
>  }
>
> +static inline unsigned int skb_tail_offset(const struct sk_buff *skb)
> +{
> + return skb->tail - skb->head;
> +}
> +
>  static inline void skb_reset_tail_pointer(struct sk_buff *skb)
>  {
>   skb->tail = skb->data;
> diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
> index eb086b06d60d..f11bb308f1ed 100644
> --- a/net/netlink/af_netlink.c
> +++ b/net/netlink/af_netlink.c
> @@ -167,7 +167,7 @@ static inline u32 netlink_group_mask(u32 group)
>  static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb,
>      gfp_t gfp_mask)
>  {
> - unsigned int len = skb_end_offset(skb);
> + unsigned int len = skb_tail_offset(skb);
>   struct sk_buff *new;
>
>   new = alloc_skb(len, gfp_mask);
>