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* [PATCH net] tun: Fix use-after-free on XDP_TX
@ 2018-07-13  4:24 Toshiaki Makita
  2018-07-13  5:05 ` Jason Wang
  2018-07-16 20:39 ` David Miller
  0 siblings, 2 replies; 4+ messages in thread
From: Toshiaki Makita @ 2018-07-13  4:24 UTC (permalink / raw)
  To: David S . Miller; +Cc: Toshiaki Makita, netdev, Jesper Dangaard Brouer

On XDP_TX we need to free up the frame only when tun_xdp_tx() returns a
negative value. A positive value indicates that the packet is
successfully enqueued to the ptr_ring, so freeing the page causes
use-after-free.

Fixes: 735fc4054b3a ("xdp: change ndo_xdp_xmit API to support bulking")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
---
 drivers/net/tun.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a192a01..f5727ba 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1688,7 +1688,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
 		case XDP_TX:
 			get_page(alloc_frag->page);
 			alloc_frag->offset += buflen;
-			if (tun_xdp_tx(tun->dev, &xdp))
+			if (tun_xdp_tx(tun->dev, &xdp) < 0)
 				goto err_redirect;
 			rcu_read_unlock();
 			local_bh_enable();
-- 
1.8.3.1

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH net] tun: Fix use-after-free on XDP_TX
  2018-07-13  4:24 [PATCH net] tun: Fix use-after-free on XDP_TX Toshiaki Makita
@ 2018-07-13  5:05 ` Jason Wang
  2018-07-13  5:57   ` Jesper Dangaard Brouer
  2018-07-16 20:39 ` David Miller
  1 sibling, 1 reply; 4+ messages in thread
From: Jason Wang @ 2018-07-13  5:05 UTC (permalink / raw)
  To: Toshiaki Makita, David S . Miller; +Cc: netdev, Jesper Dangaard Brouer



On 2018年07月13日 12:24, Toshiaki Makita wrote:
> On XDP_TX we need to free up the frame only when tun_xdp_tx() returns a
> negative value. A positive value indicates that the packet is
> successfully enqueued to the ptr_ring, so freeing the page causes
> use-after-free.
>
> Fixes: 735fc4054b3a ("xdp: change ndo_xdp_xmit API to support bulking")
> Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
> ---
>   drivers/net/tun.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index a192a01..f5727ba 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -1688,7 +1688,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
>   		case XDP_TX:
>   			get_page(alloc_frag->page);
>   			alloc_frag->offset += buflen;
> -			if (tun_xdp_tx(tun->dev, &xdp))
> +			if (tun_xdp_tx(tun->dev, &xdp) < 0)
>   				goto err_redirect;
>   			rcu_read_unlock();
>   			local_bh_enable();

Acked-by: Jason Wang <jasowang@redhat.com>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH net] tun: Fix use-after-free on XDP_TX
  2018-07-13  5:05 ` Jason Wang
@ 2018-07-13  5:57   ` Jesper Dangaard Brouer
  0 siblings, 0 replies; 4+ messages in thread
From: Jesper Dangaard Brouer @ 2018-07-13  5:57 UTC (permalink / raw)
  To: Jason Wang; +Cc: Toshiaki Makita, David S . Miller, netdev, brouer

On Fri, 13 Jul 2018 13:05:04 +0800
Jason Wang <jasowang@redhat.com> wrote:

> On 2018年07月13日 12:24, Toshiaki Makita wrote:
> > On XDP_TX we need to free up the frame only when tun_xdp_tx() returns a
> > negative value. A positive value indicates that the packet is
> > successfully enqueued to the ptr_ring, so freeing the page causes
> > use-after-free.
> >
> > Fixes: 735fc4054b3a ("xdp: change ndo_xdp_xmit API to support bulking")
> > Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
> > ---
> >   drivers/net/tun.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > index a192a01..f5727ba 100644
> > --- a/drivers/net/tun.c
> > +++ b/drivers/net/tun.c
> > @@ -1688,7 +1688,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
> >   		case XDP_TX:
> >   			get_page(alloc_frag->page);
> >   			alloc_frag->offset += buflen;
> > -			if (tun_xdp_tx(tun->dev, &xdp))
> > +			if (tun_xdp_tx(tun->dev, &xdp) < 0)
> >   				goto err_redirect;
> >   			rcu_read_unlock();
> >   			local_bh_enable();  
> 
> Acked-by: Jason Wang <jasowang@redhat.com>

Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>

Thanks for catching and fixing this!

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH net] tun: Fix use-after-free on XDP_TX
  2018-07-13  4:24 [PATCH net] tun: Fix use-after-free on XDP_TX Toshiaki Makita
  2018-07-13  5:05 ` Jason Wang
@ 2018-07-16 20:39 ` David Miller
  1 sibling, 0 replies; 4+ messages in thread
From: David Miller @ 2018-07-16 20:39 UTC (permalink / raw)
  To: makita.toshiaki; +Cc: netdev, brouer

From: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Date: Fri, 13 Jul 2018 13:24:38 +0900

> On XDP_TX we need to free up the frame only when tun_xdp_tx() returns a
> negative value. A positive value indicates that the packet is
> successfully enqueued to the ptr_ring, so freeing the page causes
> use-after-free.
> 
> Fixes: 735fc4054b3a ("xdp: change ndo_xdp_xmit API to support bulking")
> Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>

Applied, thank you.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2018-07-16 21:08 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2018-07-13  4:24 [PATCH net] tun: Fix use-after-free on XDP_TX Toshiaki Makita
2018-07-13  5:05 ` Jason Wang
2018-07-13  5:57   ` Jesper Dangaard Brouer
2018-07-16 20:39 ` David Miller

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