All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH net-next] net: dm9051: Fix use after free in dm9051_loop_tx()
@ 2022-02-18 15:27 Dan Carpenter
  2022-02-19  5:07 ` Jakub Kicinski
  0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2022-02-18 15:27 UTC (permalink / raw)
  To: David S. Miller, Joseph CHAMG; +Cc: Jakub Kicinski, netdev, kernel-janitors

This code dereferences "skb" after calling dev_kfree_skb().

Fixes: 2dc95a4d30ed ("net: Add dm9051 driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 drivers/net/ethernet/davicom/dm9051.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/davicom/dm9051.c b/drivers/net/ethernet/davicom/dm9051.c
index a63d17e669a0..f6b5d2becf5e 100644
--- a/drivers/net/ethernet/davicom/dm9051.c
+++ b/drivers/net/ethernet/davicom/dm9051.c
@@ -850,13 +850,13 @@ static int dm9051_loop_tx(struct board_info *db)
 		if (skb) {
 			ntx++;
 			ret = dm9051_single_tx(db, skb->data, skb->len);
+			ndev->stats.tx_bytes += skb->len;
+			ndev->stats.tx_packets++;
 			dev_kfree_skb(skb);
 			if (ret < 0) {
 				db->bc.tx_err_counter++;
 				return 0;
 			}
-			ndev->stats.tx_bytes += skb->len;
-			ndev->stats.tx_packets++;
 		}
 
 		if (netif_queue_stopped(ndev) &&
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH net-next] net: dm9051: Fix use after free in dm9051_loop_tx()
  2022-02-18 15:27 [PATCH net-next] net: dm9051: Fix use after free in dm9051_loop_tx() Dan Carpenter
@ 2022-02-19  5:07 ` Jakub Kicinski
  2022-02-21 10:31   ` Dan Carpenter
  0 siblings, 1 reply; 3+ messages in thread
From: Jakub Kicinski @ 2022-02-19  5:07 UTC (permalink / raw)
  To: Dan Carpenter; +Cc: David S. Miller, Joseph CHAMG, netdev, kernel-janitors

On Fri, 18 Feb 2022 18:27:30 +0300 Dan Carpenter wrote:
> This code dereferences "skb" after calling dev_kfree_skb().
> 
> Fixes: 2dc95a4d30ed ("net: Add dm9051 driver")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Thanks!  Although..

> diff --git a/drivers/net/ethernet/davicom/dm9051.c b/drivers/net/ethernet/davicom/dm9051.c
> index a63d17e669a0..f6b5d2becf5e 100644
> --- a/drivers/net/ethernet/davicom/dm9051.c
> +++ b/drivers/net/ethernet/davicom/dm9051.c
> @@ -850,13 +850,13 @@ static int dm9051_loop_tx(struct board_info *db)
>  		if (skb) {
>  			ntx++;
>  			ret = dm9051_single_tx(db, skb->data, skb->len);
> +			ndev->stats.tx_bytes += skb->len;
> +			ndev->stats.tx_packets++;
>  			dev_kfree_skb(skb);
>  			if (ret < 0) {
>  				db->bc.tx_err_counter++;
>  				return 0;
>  			}
> -			ndev->stats.tx_bytes += skb->len;
> -			ndev->stats.tx_packets++;

I think the idea was (and it often is with this kind of bugs)
to count only successful transmissions. Could you re-jig it 
a little to keep those semantics?

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH net-next] net: dm9051: Fix use after free in dm9051_loop_tx()
  2022-02-19  5:07 ` Jakub Kicinski
@ 2022-02-21 10:31   ` Dan Carpenter
  0 siblings, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2022-02-21 10:31 UTC (permalink / raw)
  To: Jakub Kicinski; +Cc: David S. Miller, Joseph CHAMG, netdev, kernel-janitors

On Fri, Feb 18, 2022 at 09:07:12PM -0800, Jakub Kicinski wrote:
> On Fri, 18 Feb 2022 18:27:30 +0300 Dan Carpenter wrote:
> > This code dereferences "skb" after calling dev_kfree_skb().
> > 
> > Fixes: 2dc95a4d30ed ("net: Add dm9051 driver")
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> Thanks!  Although..
> 
> > diff --git a/drivers/net/ethernet/davicom/dm9051.c b/drivers/net/ethernet/davicom/dm9051.c
> > index a63d17e669a0..f6b5d2becf5e 100644
> > --- a/drivers/net/ethernet/davicom/dm9051.c
> > +++ b/drivers/net/ethernet/davicom/dm9051.c
> > @@ -850,13 +850,13 @@ static int dm9051_loop_tx(struct board_info *db)
> >  		if (skb) {
> >  			ntx++;
> >  			ret = dm9051_single_tx(db, skb->data, skb->len);
> > +			ndev->stats.tx_bytes += skb->len;
> > +			ndev->stats.tx_packets++;
> >  			dev_kfree_skb(skb);
> >  			if (ret < 0) {
> >  				db->bc.tx_err_counter++;
> >  				return 0;
> >  			}
> > -			ndev->stats.tx_bytes += skb->len;
> > -			ndev->stats.tx_packets++;
> 
> I think the idea was (and it often is with this kind of bugs)
> to count only successful transmissions. Could you re-jig it 
> a little to keep those semantics?

Sure.  Will resend.

regards,
dan carpenter


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2022-02-21 11:04 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-02-18 15:27 [PATCH net-next] net: dm9051: Fix use after free in dm9051_loop_tx() Dan Carpenter
2022-02-19  5:07 ` Jakub Kicinski
2022-02-21 10:31   ` Dan Carpenter

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.