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 <[email protected]>
---
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;
+ }
+
+ /* 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;
--
1.8.3.1
> -----Original Message-----
> From: Michael Kelley (LINUX) <[email protected]>
> Sent: Saturday, February 11, 2023 5:41 PM
> To: KY Srinivasan <[email protected]>; Haiyang Zhang
> <[email protected]>; [email protected]; Dexuan Cui
> <[email protected]>; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; linux-
> [email protected]; [email protected]
> Cc: Michael Kelley (LINUX) <[email protected]>
> 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 <[email protected]>
> ---
>
> 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
From: Haiyang Zhang <[email protected]> Sent: Sunday, February 12, 2023 4:03 PM
>
> > -----Original Message-----
> > From: Michael Kelley (LINUX) <[email protected]>
> > Sent: Saturday, February 11, 2023 5:41 PM
> > To: KY Srinivasan <[email protected]>; Haiyang Zhang
> > <[email protected]>; [email protected]; Dexuan Cui
> > <[email protected]>; [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected]; linux-
> > [email protected]; [email protected]
> > Cc: Michael Kelley (LINUX) <[email protected]>
> > 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 <[email protected]>
> > ---
> >
> > 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