diff mbox series

[net] net: ravb: Fix possible UAF bug in ravb_remove

Message ID 20230309100248.3831498-1-zyytlz.wz@163.com
State New
Headers
Series [net] net: ravb: Fix possible UAF bug in ravb_remove |

Commit Message

Zheng Wang March 9, 2023, 10:02 a.m. UTC 
  In ravb_probe, priv->work was bound with ravb_tx_timeout_work.
If timeout occurs, it will start the work. And if we call
ravb_remove without finishing the work, ther may be a use
after free bug on ndev.

Fix it by finishing the job before cleanup in ravb_remove.

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
---
 drivers/net/ethernet/renesas/ravb_main.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Sergey Shtylyov March 9, 2023, 3:47 p.m. UTC | #1 
Hello!

On 3/9/23 1:02 PM, Zheng Wang wrote:

> In ravb_probe, priv->work was bound with ravb_tx_timeout_work.
> If timeout occurs, it will start the work. And if we call
> ravb_remove without finishing the work, ther may be a use
> after free bug on ndev.

   Have you actually encountered it?

> Fix it by finishing the job before cleanup in ravb_remove.
> 
> Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")

   Hm... sorry about that. :-)

> Signed-off-by: Zheng Wang <zyytlz.wz@163.com>

Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>

[...]
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 0f54849a3823..07a08e72f440 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -2892,6 +2892,7 @@ static int ravb_remove(struct platform_device *pdev)
>  	struct ravb_private *priv = netdev_priv(ndev);
>  	const struct ravb_hw_info *info = priv->info;
>  
> +	cancel_work_sync(&priv->work);

   I think we need an empty line here...

>  	/* Stop PTP Clock driver */
>  	if (info->ccc_gac)
>  		ravb_ptp_stop(ndev);

MBR, Sergey
Zheng Hacker March 10, 2023, 4:33 p.m. UTC | #2 
Sergey Shtylyov <s.shtylyov@omp.ru> 于2023年3月9日周四 23:47写道：
>
> Hello!
>
> On 3/9/23 1:02 PM, Zheng Wang wrote:
>
> > In ravb_probe, priv->work was bound with ravb_tx_timeout_work.
> > If timeout occurs, it will start the work. And if we call
> > ravb_remove without finishing the work, ther may be a use
> > after free bug on ndev.
>
>    Have you actually encountered it?

Sorry, I haven't encountered it. All of the analysis is based on
static analysis.

>
> > Fix it by finishing the job before cleanup in ravb_remove.
> >
> > Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
>
>    Hm... sorry about that. :-)
>
> > Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
>
> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
>
> [...]
> > diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> > index 0f54849a3823..07a08e72f440 100644
> > --- a/drivers/net/ethernet/renesas/ravb_main.c
> > +++ b/drivers/net/ethernet/renesas/ravb_main.c
> > @@ -2892,6 +2892,7 @@ static int ravb_remove(struct platform_device *pdev)
> >       struct ravb_private *priv = netdev_priv(ndev);
> >       const struct ravb_hw_info *info = priv->info;
> >
> > +     cancel_work_sync(&priv->work);
>
>    I think we need an empty line here...

Yes, will add it in the next version of patch.

Best regards,
Zheng

>
> >       /* Stop PTP Clock driver */
> >       if (info->ccc_gac)
> >               ravb_ptp_stop(ndev);
>
Zheng Hacker March 10, 2023, 4:38 p.m. UTC | #3 
Yunsheng Lin <linyunsheng@huawei.com> 于2023年3月10日周五 09:12写道：
>
> On 2023/3/9 18:02, Zheng Wang wrote:
> > In ravb_probe, priv->work was bound with ravb_tx_timeout_work.
> > If timeout occurs, it will start the work. And if we call
> > ravb_remove without finishing the work, ther may be a use
>
> ther -> there
>

Sorry about the typo, will correct it in the next version.

> > after free bug on ndev.
> >
> > Fix it by finishing the job before cleanup in ravb_remove.
> >
> > Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
> > Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
> > ---
> >  drivers/net/ethernet/renesas/ravb_main.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> > index 0f54849a3823..07a08e72f440 100644
> > --- a/drivers/net/ethernet/renesas/ravb_main.c
> > +++ b/drivers/net/ethernet/renesas/ravb_main.c
> > @@ -2892,6 +2892,7 @@ static int ravb_remove(struct platform_device *pdev)
> >       struct ravb_private *priv = netdev_priv(ndev);
> >       const struct ravb_hw_info *info = priv->info;
> >
> > +     cancel_work_sync(&priv->work);
>
> As your previous patch, I still do not see anything stopping
> dev_watchdog() from calling dev->netdev_ops->ndo_tx_timeout
> after cancel_work_sync(), maybe I missed something obvious
> here?
>
Yes, that's a keyed suggestion. I was hurry to report the issue today
so wrote with many mistakes.
Thanks agagin for the advice. I will review other patch carefully.

Best regards,
Zheng

>

> >       /* Stop PTP Clock driver */
> >       if (info->ccc_gac)
> >               ravb_ptp_stop(ndev);
> >
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 0f54849a3823..07a08e72f440 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2892,6 +2892,7 @@  static int ravb_remove(struct platform_device *pdev)
 	struct ravb_private *priv = netdev_priv(ndev);
 	const struct ravb_hw_info *info = priv->info;
 
+	cancel_work_sync(&priv->work);
 	/* Stop PTP Clock driver */
 	if (info->ccc_gac)
 		ravb_ptp_stop(ndev);