* [PATCH v9 3/3] hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening
2020-11-09 10:03 [PATCH v9 0/3] Drivers: hv: vmbus: vmbus_requestor data structure for VMBus hardening Andrea Parri (Microsoft)
@ 2020-11-09 10:04 ` Andrea Parri (Microsoft)
2020-11-13 11:33 ` Wei Liu
2020-11-17 10:54 ` [PATCH v9 0/3] Drivers: hv: vmbus: vmbus_requestor data structure " Wei Liu
1 sibling, 1 reply; 4+ messages in thread
From: Andrea Parri (Microsoft) @ 2020-11-09 10:04 UTC (permalink / raw)
To: linux-kernel
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger, Wei Liu,
linux-hyperv, Andres Beltran, Michael Kelley, Saruhan Karademir,
Juan Vazquez, Andrea Parri, Jakub Kicinski, David S. Miller,
netdev
From: Andres Beltran <lkmlabelt@gmail.com>
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 <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
---
Changes in v9:
- Fix order of variable declarations
Changes in v7:
- Move the allocation of the request ID after the data has been
copied into the ring buffer (cf. 1/3)
Changes in v2:
- Add casts to unsigned long to fix warnings on 32bit
- Use an inline function to get the requestor size
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..4dbc0055aed0e 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 net_device_context *ndev_ctx = netdev_priv(ndev);
+ struct sk_buff *skb;
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
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v9 0/3] Drivers: hv: vmbus: vmbus_requestor data structure for VMBus hardening
2020-11-09 10:03 [PATCH v9 0/3] Drivers: hv: vmbus: vmbus_requestor data structure for VMBus hardening Andrea Parri (Microsoft)
2020-11-09 10:04 ` [PATCH v9 3/3] hv_netvsc: Use vmbus_requestor to generate transaction IDs " Andrea Parri (Microsoft)
@ 2020-11-17 10:54 ` Wei Liu
1 sibling, 0 replies; 4+ messages in thread
From: Wei Liu @ 2020-11-17 10:54 UTC (permalink / raw)
To: Andrea Parri (Microsoft)
Cc: linux-kernel, K . Y . Srinivasan, Haiyang Zhang,
Stephen Hemminger, Wei Liu, linux-hyperv, Andres Beltran,
Michael Kelley, Saruhan Karademir, Juan Vazquez,
James E . J . Bottomley, Martin K . Petersen, David S. Miller,
Jakub Kicinski, linux-scsi, netdev
On Mon, Nov 09, 2020 at 11:03:59AM +0100, Andrea Parri (Microsoft) wrote:
> Currently, VMbus drivers use pointers into guest memory as request IDs
> for interactions with Hyper-V. To be more robust in the face of errors
> or malicious behavior from a compromised Hyper-V, avoid exposing
> guest memory addresses to Hyper-V. Also avoid Hyper-V giving back a
> bad request ID that is then treated as the address of a guest data
> structure with no validation. Instead, encapsulate these memory
> addresses and provide small integers as request IDs.
>
> The first patch creates the definitions for the data structure, provides
> helper methods to generate new IDs and retrieve data, and
> allocates/frees the memory needed for vmbus_requestor.
>
> The second and third patches make use of vmbus_requestor to send request
> IDs to Hyper-V in storvsc and netvsc respectively.
>
> The series is based on 5.10-rc3. Changelog in the actual patches.
Applied to hyperv-next. Thanks.
I also corrected the email address in my reviewed-by tags while
committing -- should've use my @kernel.org address, not @xen.org.
Wei.
^ permalink raw reply [flat|nested] 4+ messages in thread