The skb is delivered to napi_gro_receive() which may free it, after calling this,
dereferencing skb may trigger use-after-free.
Fixes: 1c59eb678cbd ("ravb: Fillup ravb_rx_gbeth() stub")
Signed-off-by: YueHaibing <[email protected]>
---
drivers/net/ethernet/renesas/ravb_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 6bc923326268..33f723a9f471 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -841,7 +841,7 @@ static bool ravb_rx_gbeth(struct net_device *ndev, int *quota, int q)
napi_gro_receive(&priv->napi[q],
priv->rx_1st_skb);
stats->rx_packets++;
- stats->rx_bytes += priv->rx_1st_skb->len;
+ stats->rx_bytes += pkt_len;
break;
}
}
--
2.34.1
Hi YueHaibing,
Thanks for the feedback.
> Subject: [PATCH net] ravb: Fix potential use-after-free in
> ravb_rx_gbeth()
>
> The skb is delivered to napi_gro_receive() which may free it, after
> calling this, dereferencing skb may trigger use-after-free.
Can you please reconfirm the changes you have done is actually fixing any issue?
If yes, please provide the details.
Current code,
napi_gro_receive(&priv->napi[q], priv->rx_1st_skb);
- stats->rx_bytes += priv->rx_1st_skb->len;
+ stats->rx_bytes += pkt_len;
Note: I haven't tested your patch yet to see it cause any regression.
Cheers,
Biju
>
> Fixes: 1c59eb678cbd ("ravb: Fillup ravb_rx_gbeth() stub")
> Signed-off-by: YueHaibing <[email protected]>
> ---
> drivers/net/ethernet/renesas/ravb_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c
> b/drivers/net/ethernet/renesas/ravb_main.c
> index 6bc923326268..33f723a9f471 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -841,7 +841,7 @@ static bool ravb_rx_gbeth(struct net_device *ndev,
> int *quota, int q)
> napi_gro_receive(&priv->napi[q],
> priv->rx_1st_skb);
> stats->rx_packets++;
> - stats->rx_bytes += priv->rx_1st_skb->len;
> + stats->rx_bytes += pkt_len;
> break;
> }
> }
> --
> 2.34.1
Hi Biju,
On Sat, Dec 3, 2022 at 11:29 AM Biju Das <[email protected]> wrote:
> > Subject: [PATCH net] ravb: Fix potential use-after-free in
> > ravb_rx_gbeth()
> >
> > The skb is delivered to napi_gro_receive() which may free it, after
> > calling this, dereferencing skb may trigger use-after-free.
>
> Can you please reconfirm the changes you have done is actually fixing any issue?
> If yes, please provide the details.
>
> Current code,
>
> napi_gro_receive(&priv->napi[q], priv->rx_1st_skb);
IIUIC, after this, priv->rx_1st_skb may have been freed...
>
> - stats->rx_bytes += priv->rx_1st_skb->len;
... so accessing priv->rx_1st_skb->len here may be a UAF.
> + stats->rx_bytes += pkt_len;
So this change looks correct to me, as pkt_len was stored to
priv->rx_1st_skb->len using skb_put() before.
Reviewed-by: Geert Uytterhoeven <[email protected]>
>
> Note: I haven't tested your patch yet to see it cause any regression.
>
> Cheers,
> Biju
>
> >
> > Fixes: 1c59eb678cbd ("ravb: Fillup ravb_rx_gbeth() stub")
> > Signed-off-by: YueHaibing <[email protected]>
> > ---
> > drivers/net/ethernet/renesas/ravb_main.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/renesas/ravb_main.c
> > b/drivers/net/ethernet/renesas/ravb_main.c
> > index 6bc923326268..33f723a9f471 100644
> > --- a/drivers/net/ethernet/renesas/ravb_main.c
> > +++ b/drivers/net/ethernet/renesas/ravb_main.c
> > @@ -841,7 +841,7 @@ static bool ravb_rx_gbeth(struct net_device *ndev,
> > int *quota, int q)
> > napi_gro_receive(&priv->napi[q],
> > priv->rx_1st_skb);
> > stats->rx_packets++;
> > - stats->rx_bytes += priv->rx_1st_skb->len;
> > + stats->rx_bytes += pkt_len;
> > break;
> > }
> > }
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Hi Geert,
> Subject: Re: [PATCH net] ravb: Fix potential use-after-free in
> ravb_rx_gbeth()
>
> Hi Biju,
>
> On Sat, Dec 3, 2022 at 11:29 AM Biju Das <[email protected]>
> wrote:
> > > Subject: [PATCH net] ravb: Fix potential use-after-free in
> > > ravb_rx_gbeth()
> > >
> > > The skb is delivered to napi_gro_receive() which may free it, after
> > > calling this, dereferencing skb may trigger use-after-free.
> >
> > Can you please reconfirm the changes you have done is actually fixing
> any issue?
> > If yes, please provide the details.
> >
> > Current code,
> >
> > napi_gro_receive(&priv->napi[q], priv->rx_1st_skb);
>
> IIUIC, after this, priv->rx_1st_skb may have been freed...
>
> >
> > - stats->rx_bytes += priv->rx_1st_skb->len;
>
> ... so accessing priv->rx_1st_skb->len here may be a UAF.
>
> > + stats->rx_bytes += pkt_len;
>
> So this change looks correct to me, as pkt_len was stored to
> priv->rx_1st_skb->len using skb_put() before.
Thanks for detailed explanation. It makes sense now.
Cheers,
Biju
>
> Reviewed-by: Geert Uytterhoeven <[email protected]>
>
> >
> > Note: I haven't tested your patch yet to see it cause any regression.
> >
> > Cheers,
> > Biju
> >
> > >
> > > Fixes: 1c59eb678cbd ("ravb: Fillup ravb_rx_gbeth() stub")
> > > Signed-off-by: YueHaibing <[email protected]>
> > > ---
> > > drivers/net/ethernet/renesas/ravb_main.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/net/ethernet/renesas/ravb_main.c
> > > b/drivers/net/ethernet/renesas/ravb_main.c
> > > index 6bc923326268..33f723a9f471 100644
> > > --- a/drivers/net/ethernet/renesas/ravb_main.c
> > > +++ b/drivers/net/ethernet/renesas/ravb_main.c
> > > @@ -841,7 +841,7 @@ static bool ravb_rx_gbeth(struct net_device
> > > *ndev, int *quota, int q)
> > > napi_gro_receive(&priv->napi[q],
> > > priv->rx_1st_skb);
> > > stats->rx_packets++;
> > > - stats->rx_bytes += priv->rx_1st_skb-
> >len;
> > > + stats->rx_bytes += pkt_len;
> > > break;
> > > }
> > > }
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker.
> But when I'm talking to journalists I just say "programmer" or something
> like that.
> -- Linus Torvalds
Hello:
This patch was applied to netdev/net.git (master)
by Paolo Abeni <[email protected]>:
On Sat, 3 Dec 2022 17:29:41 +0800 you wrote:
> The skb is delivered to napi_gro_receive() which may free it, after calling this,
> dereferencing skb may trigger use-after-free.
>
> Fixes: 1c59eb678cbd ("ravb: Fillup ravb_rx_gbeth() stub")
> Signed-off-by: YueHaibing <[email protected]>
> ---
> drivers/net/ethernet/renesas/ravb_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Here is the summary with links:
- [net] ravb: Fix potential use-after-free in ravb_rx_gbeth()
https://git.kernel.org/netdev/net/c/5a5a3e564de6
You are awesome, thank you!
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