diff mbox series

[net-next,v2,1/1] hv_netvsc: Check status in SEND_RNDIS_PKT completion message

Message ID 1676155276-36609-1-git-send-email-mikelley@microsoft.com
State New
Headers
Series [net-next,v2,1/1] hv_netvsc: Check status in SEND_RNDIS_PKT completion message |

Commit Message

Michael Kelley (LINUX) Feb. 11, 2023, 10:41 p.m. UTC 
  Completion responses to SEND_RNDIS_PKT messages are currently processed
regardless of the status in the response, so that resources associated
with the request are freed.  While this is appropriate, code bugs that
cause sending a malformed message, or errors on the Hyper-V host, go
undetected. Fix this by checking the status and outputting a rate-limited
message if there is an error.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---

Changes in v2:
* Add rate-limiting to error messages [Haiyang Zhang]

 drivers/net/hyperv/netvsc.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

Comments

Haiyang Zhang Feb. 13, 2023, 12:02 a.m. UTC | #1 
> -----Original Message-----
> From: Michael Kelley (LINUX) <mikelley@microsoft.com>
> Sent: Saturday, February 11, 2023 5:41 PM
> To: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
> <haiyangz@microsoft.com>; wei.liu@kernel.org; Dexuan Cui
> <decui@microsoft.com>; davem@davemloft.net; edumazet@google.com;
> kuba@kernel.org; pabeni@redhat.com; netdev@vger.kernel.org; linux-
> hyperv@vger.kernel.org; linux-kernel@vger.kernel.org
> Cc: Michael Kelley (LINUX) <mikelley@microsoft.com>
> Subject: [PATCH net-next v2 1/1] hv_netvsc: Check status in
> SEND_RNDIS_PKT completion message
> 
> Completion responses to SEND_RNDIS_PKT messages are currently processed
> regardless of the status in the response, so that resources associated
> with the request are freed.  While this is appropriate, code bugs that
> cause sending a malformed message, or errors on the Hyper-V host, go
> undetected. Fix this by checking the status and outputting a rate-limited
> message if there is an error.
> 
> Signed-off-by: Michael Kelley <mikelley@microsoft.com>
> ---
> 
> Changes in v2:
> * Add rate-limiting to error messages [Haiyang Zhang]
> 
>  drivers/net/hyperv/netvsc.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
> index 661bbe6..90f10ac 100644
> --- a/drivers/net/hyperv/netvsc.c
> +++ b/drivers/net/hyperv/netvsc.c
> @@ -813,6 +813,7 @@ static void netvsc_send_completion(struct net_device
> *ndev,
>  	u32 msglen = hv_pkt_datalen(desc);
>  	struct nvsp_message *pkt_rqst;
>  	u64 cmd_rqst;
> +	u32 status;
> 
>  	/* First check if this is a VMBUS completion without data payload */
>  	if (!msglen) {
> @@ -884,6 +885,23 @@ static void netvsc_send_completion(struct
> net_device *ndev,
>  		break;
> 
>  	case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
> +		if (msglen < sizeof(struct nvsp_message_header) +
> +		    sizeof(struct
> nvsp_1_message_send_rndis_packet_complete) &&
> +		    net_ratelimit()) {
> +			netdev_err(ndev, "nvsp_rndis_pkt_complete length
> too small: %u\n",
> +				   msglen);
> +			return;
> +		}

The net_ratelimit() condition should be for the error print only, not affect
the "return".

Thanks,
- Haiyang
Michael Kelley (LINUX) Feb. 13, 2023, 1 a.m. UTC | #2 
From: Haiyang Zhang <haiyangz@microsoft.com> Sent: Sunday, February 12, 2023 4:03 PM
> 
> > -----Original Message-----
> > From: Michael Kelley (LINUX) <mikelley@microsoft.com>
> > Sent: Saturday, February 11, 2023 5:41 PM
> > To: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
> > <haiyangz@microsoft.com>; wei.liu@kernel.org; Dexuan Cui
> > <decui@microsoft.com>; davem@davemloft.net; edumazet@google.com;
> > kuba@kernel.org; pabeni@redhat.com; netdev@vger.kernel.org; linux-
> > hyperv@vger.kernel.org; linux-kernel@vger.kernel.org
> > Cc: Michael Kelley (LINUX) <mikelley@microsoft.com>
> > Subject: [PATCH net-next v2 1/1] hv_netvsc: Check status in
> > SEND_RNDIS_PKT completion message
> >
> > Completion responses to SEND_RNDIS_PKT messages are currently processed
> > regardless of the status in the response, so that resources associated
> > with the request are freed.  While this is appropriate, code bugs that
> > cause sending a malformed message, or errors on the Hyper-V host, go
> > undetected. Fix this by checking the status and outputting a rate-limited
> > message if there is an error.
> >
> > Signed-off-by: Michael Kelley <mikelley@microsoft.com>
> > ---
> >
> > Changes in v2:
> > * Add rate-limiting to error messages [Haiyang Zhang]
> >
> >  drivers/net/hyperv/netvsc.c | 18 ++++++++++++++++++
> >  1 file changed, 18 insertions(+)
> >
> > diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
> > index 661bbe6..90f10ac 100644
> > --- a/drivers/net/hyperv/netvsc.c
> > +++ b/drivers/net/hyperv/netvsc.c
> > @@ -813,6 +813,7 @@ static void netvsc_send_completion(struct net_device
> > *ndev,
> >  	u32 msglen = hv_pkt_datalen(desc);
> >  	struct nvsp_message *pkt_rqst;
> >  	u64 cmd_rqst;
> > +	u32 status;
> >
> >  	/* First check if this is a VMBUS completion without data payload */
> >  	if (!msglen) {
> > @@ -884,6 +885,23 @@ static void netvsc_send_completion(struct
> > net_device *ndev,
> >  		break;
> >
> >  	case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
> > +		if (msglen < sizeof(struct nvsp_message_header) +
> > +		    sizeof(struct nvsp_1_message_send_rndis_packet_complete) &&
> > +		    net_ratelimit()) {
> > +			netdev_err(ndev, "nvsp_rndis_pkt_complete length too small: %u\n",
> > +				   msglen);
> > +			return;
> > +		}
> 
> The net_ratelimit() condition should be for the error print only, not affect
> the "return".

Argh.  :-(   You're right.  Will fix in v3.

Michael
diff mbox series

Patch

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 661bbe6..90f10ac 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -813,6 +813,7 @@  static void netvsc_send_completion(struct net_device *ndev,
 	u32 msglen = hv_pkt_datalen(desc);
 	struct nvsp_message *pkt_rqst;
 	u64 cmd_rqst;
+	u32 status;
 
 	/* First check if this is a VMBUS completion without data payload */
 	if (!msglen) {
@@ -884,6 +885,23 @@  static void netvsc_send_completion(struct net_device *ndev,
 		break;
 
 	case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
+		if (msglen < sizeof(struct nvsp_message_header) +
+		    sizeof(struct nvsp_1_message_send_rndis_packet_complete) &&
+		    net_ratelimit()) {
+			netdev_err(ndev, "nvsp_rndis_pkt_complete length too small: %u\n",
+				   msglen);
+			return;
+		}
+
+		/* If status indicates an error, output a message so we know
+		 * there's a problem. But process the completion anyway so the
+		 * resources are released.
+		 */
+		status = nvsp_packet->msg.v1_msg.send_rndis_pkt_complete.status;
+		if (status != NVSP_STAT_SUCCESS && net_ratelimit())
+			netdev_err(ndev, "nvsp_rndis_pkt_complete error status: %x\n",
+				   status);
+
 		netvsc_send_tx_complete(ndev, net_device, incoming_channel,
 					desc, budget);
 		break;