linux-kernel - Re: [PATCH net-next] tun: use xdp_get_frame

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <681bc8f326126_20e9e6294b1@willemb.c.googlers.com.notmuch>
Date: Wed, 07 May 2025 16:56:19 -0400
From: Willem de Bruijn <willemdebruijn.kernel@...il.com>
To: Jon Kohler <jon@...anix.com>, 
 Willem de Bruijn <willemdebruijn.kernel@...il.com>, 
 Jason Wang <jasowang@...hat.com>, 
 Andrew Lunn <andrew+netdev@...n.ch>, 
 "David S. Miller" <davem@...emloft.net>, 
 Eric Dumazet <edumazet@...gle.com>, 
 Jakub Kicinski <kuba@...nel.org>, 
 Paolo Abeni <pabeni@...hat.com>, 
 Alexei Starovoitov <ast@...nel.org>, 
 Daniel Borkmann <daniel@...earbox.net>, 
 Jesper Dangaard Brouer <hawk@...nel.org>, 
 John Fastabend <john.fastabend@...il.com>, 
 netdev@...r.kernel.org, 
 linux-kernel@...r.kernel.org, 
 bpf@...r.kernel.org
Cc: Jon Kohler <jon@...anix.com>
Subject: Re: [PATCH net-next] tun: use xdp_get_frame_len()

Jon Kohler wrote:
> Use xdp_get_frame_len helper to ensure xdp frame size is calculated
> correctly in both single buffer and multi buffer configurations.

Not necessarily opposed, but multi buffer is not actually possible
in this code path, right?

tun_put_user_xdp only copies xdp_frame->data, for one.

Else this would also be fix, not net-next material.
> 
> Signed-off-by: Jon Kohler <jon@...anix.com>
> ---
>  drivers/net/tun.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index 7babd1e9a378..1c879467e696 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -1993,7 +1993,7 @@ static ssize_t tun_put_user_xdp(struct tun_struct *tun,
>  				struct iov_iter *iter)
>  {
>  	int vnet_hdr_sz = 0;
> -	size_t size = xdp_frame->len;
> +	size_t size = xdp_get_frame_len(xdp_frame);
>  	ssize_t ret;
>  
>  	if (tun->flags & IFF_VNET_HDR) {
> @@ -2579,7 +2579,7 @@ static int tun_ptr_peek_len(void *ptr)
>  		if (tun_is_xdp_frame(ptr)) {
>  			struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
>  
> -			return xdpf->len;
> +			return xdp_get_frame_len(xdpf);
>  		}
>  		return __skb_array_len_with_tag(ptr);
>  	} else {
> -- 
> 2.43.0
>