diff mbox

[net] drivers: net: xgene: fix possible use after free

Message ID 1448470930.24696.10.camel@edumazet-glaptop2.roam.corp.google.com (mailing list archive)
State New, archived
Headers show

Commit Message

Eric Dumazet Nov. 25, 2015, 5:02 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

Once TX has been enabled on a NIC, it is illegal to access skb,
as this skb might have been freed by another cpu, from TX completion
handler.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Iyappan Subramanian <isubramanian@apm.com>
---
 drivers/net/ethernet/apm/xgene/xgene_enet_main.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Iyappan Subramanian Nov. 28, 2015, 3:34 a.m. UTC | #1 
On Wed, Nov 25, 2015 at 9:02 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> Once TX has been enabled on a NIC, it is illegal to access skb,
> as this skb might have been freed by another cpu, from TX completion
> handler.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Mark Rutland <mark.rutland@arm.com>
> Tested-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Iyappan Subramanian <isubramanian@apm.com>
> ---
>  drivers/net/ethernet/apm/xgene/xgene_enet_main.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
> index 1adfe7036843..9147a0107c44 100644
> --- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
> +++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
> @@ -450,12 +450,12 @@ static netdev_tx_t xgene_enet_start_xmit(struct sk_buff *skb,
>                 return NETDEV_TX_OK;
>         }
>
> -       pdata->ring_ops->wr_cmd(tx_ring, count);
>         skb_tx_timestamp(skb);
>
>         pdata->stats.tx_packets++;
>         pdata->stats.tx_bytes += skb->len;
>
> +       pdata->ring_ops->wr_cmd(tx_ring, count);

Thanks Mark and Eric, for the fix.

Acked-by: Iyappan Subramanian <isubramanian@apm.com>

>         return NETDEV_TX_OK;
>  }
>
>
>
David Miller Nov. 30, 2015, 3:52 a.m. UTC | #2 
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 25 Nov 2015 09:02:10 -0800

> From: Eric Dumazet <edumazet@google.com>
> 
> Once TX has been enabled on a NIC, it is illegal to access skb,
> as this skb might have been freed by another cpu, from TX completion
> handler.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Mark Rutland <mark.rutland@arm.com>
> Tested-by: Mark Rutland <mark.rutland@arm.com>

Applied, thanks Eric.
diff mbox

Patch

diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
index 1adfe7036843..9147a0107c44 100644
--- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
@@ -450,12 +450,12 @@  static netdev_tx_t xgene_enet_start_xmit(struct sk_buff *skb,
 		return NETDEV_TX_OK;
 	}
 
-	pdata->ring_ops->wr_cmd(tx_ring, count);
 	skb_tx_timestamp(skb);
 
 	pdata->stats.tx_packets++;
 	pdata->stats.tx_bytes += skb->len;
 
+	pdata->ring_ops->wr_cmd(tx_ring, count);
 	return NETDEV_TX_OK;
 }