2020-11-04 15:44:58

by Andrea Parri

[permalink] [raw]
Subject: [PATCH v8 0/3] Drivers: hv: vmbus: vmbus_requestor data structure for VMBus hardening

Hi all,

This is a resubmission of:

https://lkml.kernel.org/r/[email protected]

based on 5.10-rc2.

Andrea

Cc: James E.J. Bottomley <[email protected]>
Cc: Martin K. Petersen <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: [email protected]
Cc: [email protected]

Andres Beltran (3):
Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus
hardening
scsi: storvsc: Use vmbus_requestor to generate transaction IDs for
VMBus hardening
hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus
hardening

drivers/hv/channel.c | 174 ++++++++++++++++++++++++++++--
drivers/hv/hyperv_vmbus.h | 3 +-
drivers/hv/ring_buffer.c | 28 ++++-
drivers/net/hyperv/hyperv_net.h | 13 +++
drivers/net/hyperv/netvsc.c | 22 ++--
drivers/net/hyperv/rndis_filter.c | 1 +
drivers/scsi/storvsc_drv.c | 26 ++++-
include/linux/hyperv.h | 23 ++++
8 files changed, 272 insertions(+), 18 deletions(-)

--
2.25.1


2020-11-04 15:45:01

by Andrea Parri

[permalink] [raw]
Subject: [PATCH v8 3/3] hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening

From: Andres Beltran <[email protected]>

Currently, pointers to guest memory are passed to Hyper-V as
transaction IDs in netvsc. In the face of errors or malicious
behavior in Hyper-V, netvsc should not expose or trust the transaction
IDs returned by Hyper-V to be valid guest memory addresses. Instead,
use small integers generated by vmbus_requestor as requests
(transaction) IDs.

Signed-off-by: Andres Beltran <[email protected]>
Co-developed-by: Andrea Parri (Microsoft) <[email protected]>
Signed-off-by: Andrea Parri (Microsoft) <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: [email protected]
---
drivers/net/hyperv/hyperv_net.h | 13 +++++++++++++
drivers/net/hyperv/netvsc.c | 22 ++++++++++++++++------
drivers/net/hyperv/rndis_filter.c | 1 +
include/linux/hyperv.h | 1 +
4 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index a0f338cf14247..2a87cfa27ac02 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -847,6 +847,19 @@ struct nvsp_message {

#define NETVSC_XDP_HDRM 256

+#define NETVSC_MIN_OUT_MSG_SIZE (sizeof(struct vmpacket_descriptor) + \
+ sizeof(struct nvsp_message))
+#define NETVSC_MIN_IN_MSG_SIZE sizeof(struct vmpacket_descriptor)
+
+/* Estimated requestor size:
+ * out_ring_size/min_out_msg_size + in_ring_size/min_in_msg_size
+ */
+static inline u32 netvsc_rqstor_size(unsigned long ringbytes)
+{
+ return ringbytes / NETVSC_MIN_OUT_MSG_SIZE +
+ ringbytes / NETVSC_MIN_IN_MSG_SIZE;
+}
+
#define NETVSC_XFER_HEADER_SIZE(rng_cnt) \
(offsetof(struct vmtransfer_page_packet_header, ranges) + \
(rng_cnt) * sizeof(struct vmtransfer_page_range))
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 0c3de94b51787..f74ee8b90b84d 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -50,7 +50,7 @@ void netvsc_switch_datapath(struct net_device *ndev, bool vf)

vmbus_sendpacket(dev->channel, init_pkt,
sizeof(struct nvsp_message),
- (unsigned long)init_pkt,
+ VMBUS_RQST_ID_NO_RESPONSE,
VM_PKT_DATA_INBAND, 0);
}

@@ -163,7 +163,7 @@ static void netvsc_revoke_recv_buf(struct hv_device *device,
ret = vmbus_sendpacket(device->channel,
revoke_packet,
sizeof(struct nvsp_message),
- (unsigned long)revoke_packet,
+ VMBUS_RQST_ID_NO_RESPONSE,
VM_PKT_DATA_INBAND, 0);
/* If the failure is because the channel is rescinded;
* ignore the failure since we cannot send on a rescinded
@@ -213,7 +213,7 @@ static void netvsc_revoke_send_buf(struct hv_device *device,
ret = vmbus_sendpacket(device->channel,
revoke_packet,
sizeof(struct nvsp_message),
- (unsigned long)revoke_packet,
+ VMBUS_RQST_ID_NO_RESPONSE,
VM_PKT_DATA_INBAND, 0);

/* If the failure is because the channel is rescinded;
@@ -557,7 +557,7 @@ static int negotiate_nvsp_ver(struct hv_device *device,

ret = vmbus_sendpacket(device->channel, init_packet,
sizeof(struct nvsp_message),
- (unsigned long)init_packet,
+ VMBUS_RQST_ID_NO_RESPONSE,
VM_PKT_DATA_INBAND, 0);

return ret;
@@ -614,7 +614,7 @@ static int netvsc_connect_vsp(struct hv_device *device,
/* Send the init request */
ret = vmbus_sendpacket(device->channel, init_packet,
sizeof(struct nvsp_message),
- (unsigned long)init_packet,
+ VMBUS_RQST_ID_NO_RESPONSE,
VM_PKT_DATA_INBAND, 0);
if (ret != 0)
goto cleanup;
@@ -695,10 +695,19 @@ static void netvsc_send_tx_complete(struct net_device *ndev,
const struct vmpacket_descriptor *desc,
int budget)
{
- struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
+ struct sk_buff *skb;
struct net_device_context *ndev_ctx = netdev_priv(ndev);
u16 q_idx = 0;
int queue_sends;
+ u64 cmd_rqst;
+
+ cmd_rqst = vmbus_request_addr(&channel->requestor, (u64)desc->trans_id);
+ if (cmd_rqst == VMBUS_RQST_ERROR) {
+ netdev_err(ndev, "Incorrect transaction id\n");
+ return;
+ }
+
+ skb = (struct sk_buff *)(unsigned long)cmd_rqst;

/* Notify the layer above us */
if (likely(skb)) {
@@ -1520,6 +1529,7 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device,
netvsc_poll, NAPI_POLL_WEIGHT);

/* Open the channel */
+ device->channel->rqstor_size = netvsc_rqstor_size(netvsc_ring_bytes);
ret = vmbus_open(device->channel, netvsc_ring_bytes,
netvsc_ring_bytes, NULL, 0,
netvsc_channel_cb, net_device->chan_table);
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index b22e47bcfeca1..6ae43319ece68 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1172,6 +1172,7 @@ static void netvsc_sc_open(struct vmbus_channel *new_sc)
/* Set the channel before opening.*/
nvchan->channel = new_sc;

+ new_sc->rqstor_size = netvsc_rqstor_size(netvsc_ring_bytes);
ret = vmbus_open(new_sc, netvsc_ring_bytes,
netvsc_ring_bytes, NULL, 0,
netvsc_channel_cb, nvchan);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 5b6d5c4e37110..5ddb479c4d4cb 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -779,6 +779,7 @@ struct vmbus_requestor {

#define VMBUS_NO_RQSTOR U64_MAX
#define VMBUS_RQST_ERROR (U64_MAX - 1)
+#define VMBUS_RQST_ID_NO_RESPONSE (U64_MAX - 2)

struct vmbus_device {
u16 dev_type;
--
2.25.1

2020-11-04 15:45:47

by Andrea Parri

[permalink] [raw]
Subject: [PATCH v8 2/3] scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening

From: Andres Beltran <[email protected]>

Currently, pointers to guest memory are passed to Hyper-V as
transaction IDs in storvsc. In the face of errors or malicious
behavior in Hyper-V, storvsc should not expose or trust the transaction
IDs returned by Hyper-V to be valid guest memory addresses. Instead,
use small integers generated by vmbus_requestor as requests
(transaction) IDs.

Signed-off-by: Andres Beltran <[email protected]>
Co-developed-by: Andrea Parri (Microsoft) <[email protected]>
Signed-off-by: Andrea Parri (Microsoft) <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: [email protected]
---
drivers/scsi/storvsc_drv.c | 26 +++++++++++++++++++++++---
1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 0c65fbd41035e..369a6c6266729 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -399,6 +399,7 @@ static int storvsc_timeout = 180;
static struct scsi_transport_template *fc_transport_template;
#endif

+static struct scsi_host_template scsi_driver;
static void storvsc_on_channel_callback(void *context);

#define STORVSC_MAX_LUNS_PER_TARGET 255
@@ -698,6 +699,12 @@ static void handle_sc_creation(struct vmbus_channel *new_sc)

memset(&props, 0, sizeof(struct vmstorage_channel_properties));

+ /*
+ * The size of vmbus_requestor is an upper bound on the number of requests
+ * that can be in-progress at any one time across all channels.
+ */
+ new_sc->rqstor_size = scsi_driver.can_queue;
+
ret = vmbus_open(new_sc,
storvsc_ringbuffer_size,
storvsc_ringbuffer_size,
@@ -1242,9 +1249,17 @@ static void storvsc_on_channel_callback(void *context)
foreach_vmbus_pkt(desc, channel) {
void *packet = hv_pkt_data(desc);
struct storvsc_cmd_request *request;
+ u64 cmd_rqst;
+
+ cmd_rqst = vmbus_request_addr(&channel->requestor,
+ desc->trans_id);
+ if (cmd_rqst == VMBUS_RQST_ERROR) {
+ dev_err(&device->device,
+ "Incorrect transaction id\n");
+ continue;
+ }

- request = (struct storvsc_cmd_request *)
- ((unsigned long)desc->trans_id);
+ request = (struct storvsc_cmd_request *)(unsigned long)cmd_rqst;

if (request == &stor_device->init_request ||
request == &stor_device->reset_request) {
@@ -1265,6 +1280,12 @@ static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,

memset(&props, 0, sizeof(struct vmstorage_channel_properties));

+ /*
+ * The size of vmbus_requestor is an upper bound on the number of requests
+ * that can be in-progress at any one time across all channels.
+ */
+ device->channel->rqstor_size = scsi_driver.can_queue;
+
ret = vmbus_open(device->channel,
ring_size,
ring_size,
@@ -1572,7 +1593,6 @@ static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
struct vstor_packet *vstor_packet;
int ret, t;

-
stor_device = get_out_stor_device(device);
if (!stor_device)
return FAILED;
--
2.25.1

2020-11-04 21:46:33

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH v8 3/3] hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening

On Wed, 4 Nov 2020 16:40:27 +0100 Andrea Parri (Microsoft) wrote:
> From: Andres Beltran <[email protected]>
>
> Currently, pointers to guest memory are passed to Hyper-V as
> transaction IDs in netvsc. In the face of errors or malicious
> behavior in Hyper-V, netvsc should not expose or trust the transaction
> IDs returned by Hyper-V to be valid guest memory addresses. Instead,
> use small integers generated by vmbus_requestor as requests
> (transaction) IDs.
>
> Signed-off-by: Andres Beltran <[email protected]>
> Co-developed-by: Andrea Parri (Microsoft) <[email protected]>
> Signed-off-by: Andrea Parri (Microsoft) <[email protected]>
> Reviewed-by: Michael Kelley <[email protected]>

I'm assuming this is targeting net-next? If so could you please tag it
as [PATCH net-next vN]?

> @@ -695,10 +695,19 @@ static void netvsc_send_tx_complete(struct net_device *ndev,
> const struct vmpacket_descriptor *desc,
> int budget)
> {
> - struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
> + struct sk_buff *skb;
> struct net_device_context *ndev_ctx = netdev_priv(ndev);

Swap these two lines please to keep the variables declaration lines
longest to shortest.

2020-11-04 21:47:22

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH v8 3/3] hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening

On Wed, 4 Nov 2020 13:43:48 -0800 Jakub Kicinski wrote:
> On Wed, 4 Nov 2020 16:40:27 +0100 Andrea Parri (Microsoft) wrote:
> > From: Andres Beltran <[email protected]>
> >
> > Currently, pointers to guest memory are passed to Hyper-V as
> > transaction IDs in netvsc. In the face of errors or malicious
> > behavior in Hyper-V, netvsc should not expose or trust the transaction
> > IDs returned by Hyper-V to be valid guest memory addresses. Instead,
> > use small integers generated by vmbus_requestor as requests
> > (transaction) IDs.
> >
> > Signed-off-by: Andres Beltran <[email protected]>
> > Co-developed-by: Andrea Parri (Microsoft) <[email protected]>
> > Signed-off-by: Andrea Parri (Microsoft) <[email protected]>
> > Reviewed-by: Michael Kelley <[email protected]>
>
> I'm assuming this is targeting net-next? If so could you please tag it
> as [PATCH net-next vN]?

Ah, you don't 'cause you only sent us the third patch. In that case with
the nit below addressed:

Acked-by: Jakub Kicinski <[email protected]>

> > @@ -695,10 +695,19 @@ static void netvsc_send_tx_complete(struct net_device *ndev,
> > const struct vmpacket_descriptor *desc,
> > int budget)
> > {
> > - struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
> > + struct sk_buff *skb;
> > struct net_device_context *ndev_ctx = netdev_priv(ndev);
>
> Swap these two lines please to keep the variables declaration lines
> longest to shortest.

2020-11-05 05:02:46

by Andrea Parri

[permalink] [raw]
Subject: Re: [PATCH v8 3/3] hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening

On Wed, Nov 04, 2020 at 01:45:05PM -0800, Jakub Kicinski wrote:
> On Wed, 4 Nov 2020 13:43:48 -0800 Jakub Kicinski wrote:
> > On Wed, 4 Nov 2020 16:40:27 +0100 Andrea Parri (Microsoft) wrote:
> > > From: Andres Beltran <[email protected]>
> > >
> > > Currently, pointers to guest memory are passed to Hyper-V as
> > > transaction IDs in netvsc. In the face of errors or malicious
> > > behavior in Hyper-V, netvsc should not expose or trust the transaction
> > > IDs returned by Hyper-V to be valid guest memory addresses. Instead,
> > > use small integers generated by vmbus_requestor as requests
> > > (transaction) IDs.
> > >
> > > Signed-off-by: Andres Beltran <[email protected]>
> > > Co-developed-by: Andrea Parri (Microsoft) <[email protected]>
> > > Signed-off-by: Andrea Parri (Microsoft) <[email protected]>
> > > Reviewed-by: Michael Kelley <[email protected]>
> >
> > I'm assuming this is targeting net-next? If so could you please tag it
> > as [PATCH net-next vN]?
>
> Ah, you don't 'cause you only sent us the third patch. In that case with
> the nit below addressed:
>
> Acked-by: Jakub Kicinski <[email protected]>

I fixed the declarations locally. Thank you for the review, Jakub.

(Yes, FWIW, I was imaging the series to go via hyperv-next...)

Thanks,
Andrea


>
> > > @@ -695,10 +695,19 @@ static void netvsc_send_tx_complete(struct net_device *ndev,
> > > const struct vmpacket_descriptor *desc,
> > > int budget)
> > > {
> > > - struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
> > > + struct sk_buff *skb;
> > > struct net_device_context *ndev_ctx = netdev_priv(ndev);
> >
> > Swap these two lines please to keep the variables declaration lines
> > longest to shortest.
>