Linux-HyperV Archive on lore.kernel.org
 help / color / Atom feed
From: Andres Beltran <lkmlabelt@gmail.com>
To: kys@microsoft.com, haiyangz@microsoft.com,
	sthemmin@microsoft.com, wei.liu@kernel.org
Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
	mikelley@microsoft.com, parri.andrea@gmail.com,
	Andres Beltran <lkmlabelt@gmail.com>,
	"David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	netdev@vger.kernel.org
Subject: [PATCH v2 3/3] hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening
Date: Mon, 29 Jun 2020 16:02:27 -0400
Message-ID: <20200629200227.1518784-4-lkmlabelt@gmail.com> (raw)
In-Reply-To: <20200629200227.1518784-1-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.

Cc: David S. Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
---
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       | 79 +++++++++++++++++++++++++------
 drivers/net/hyperv/rndis_filter.c |  1 +
 include/linux/hyperv.h            |  1 +
 4 files changed, 80 insertions(+), 14 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index abda736e7c7d..f43b614f2345 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;
+}
+
 struct multi_send_data {
 	struct sk_buff *skb; /* skb containing the pkt */
 	struct hv_netvsc_packet *pkt; /* netvsc pkt pending */
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 41f5cf0bb997..79b907a29433 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;
@@ -304,6 +304,7 @@ static int netvsc_init_buf(struct hv_device *device,
 	unsigned int buf_size;
 	size_t map_words;
 	int ret = 0;
+	u64 rqst_id;
 
 	/* Get receive buffer area. */
 	buf_size = device_info->recv_sections * device_info->recv_section_size;
@@ -350,13 +351,22 @@ static int netvsc_init_buf(struct hv_device *device,
 
 	trace_nvsp_send(ndev, init_packet);
 
+	rqst_id = vmbus_next_request_id(&device->channel->requestor,
+					(unsigned long)init_packet);
+	if (rqst_id == VMBUS_RQST_ERROR) {
+		netdev_err(ndev, "No request id available\n");
+		goto cleanup;
+	}
+
 	/* Send the gpadl notification request */
 	ret = vmbus_sendpacket(device->channel, init_packet,
 			       sizeof(struct nvsp_message),
-			       (unsigned long)init_packet,
+			       rqst_id,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 	if (ret != 0) {
+		/* Reclaim request ID to avoid leak of IDs */
+		vmbus_request_addr(&device->channel->requestor, rqst_id);
 		netdev_err(ndev,
 			"unable to send receive buffer's gpadl to netvsp\n");
 		goto cleanup;
@@ -432,13 +442,22 @@ static int netvsc_init_buf(struct hv_device *device,
 
 	trace_nvsp_send(ndev, init_packet);
 
+	rqst_id = vmbus_next_request_id(&device->channel->requestor,
+					(unsigned long)init_packet);
+	if (rqst_id == VMBUS_RQST_ERROR) {
+		netdev_err(ndev, "No request id available\n");
+		goto cleanup;
+	}
+
 	/* Send the gpadl notification request */
 	ret = vmbus_sendpacket(device->channel, init_packet,
 			       sizeof(struct nvsp_message),
-			       (unsigned long)init_packet,
+			       rqst_id,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 	if (ret != 0) {
+		/* Reclaim request ID to avoid leak of IDs */
+		vmbus_request_addr(&device->channel->requestor, rqst_id);
 		netdev_err(ndev,
 			   "unable to send send buffer's gpadl to netvsp\n");
 		goto cleanup;
@@ -496,6 +515,7 @@ static int negotiate_nvsp_ver(struct hv_device *device,
 {
 	struct net_device *ndev = hv_get_drvdata(device);
 	int ret;
+	u64 rqst_id;
 
 	memset(init_packet, 0, sizeof(struct nvsp_message));
 	init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
@@ -503,15 +523,25 @@ static int negotiate_nvsp_ver(struct hv_device *device,
 	init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 	trace_nvsp_send(ndev, init_packet);
 
+	rqst_id = vmbus_next_request_id(&device->channel->requestor,
+					(unsigned long)init_packet);
+	if (rqst_id == VMBUS_RQST_ERROR) {
+		netdev_err(ndev, "No request id available\n");
+		return -EAGAIN;
+	}
+
 	/* Send the init request */
 	ret = vmbus_sendpacket(device->channel, init_packet,
 			       sizeof(struct nvsp_message),
-			       (unsigned long)init_packet,
+			       rqst_id,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 
-	if (ret != 0)
+	if (ret != 0) {
+		/* Reclaim request ID to avoid leak of IDs */
+		vmbus_request_addr(&device->channel->requestor, rqst_id);
 		return ret;
+	}
 
 	wait_for_completion(&net_device->channel_init_wait);
 
@@ -542,7 +572,7 @@ 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;
@@ -599,7 +629,7 @@ 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;
@@ -680,10 +710,19 @@ 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)) {
@@ -822,7 +861,7 @@ static inline int netvsc_send_pkt(
 	struct net_device *ndev = hv_get_drvdata(device);
 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
 	struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
-	u64 req_id;
+	u64 rqst_id;
 	int ret;
 	u32 ring_avail = hv_get_avail_to_write_percent(&out_channel->outbound);
 
@@ -838,13 +877,19 @@ static inline int netvsc_send_pkt(
 	else
 		rpkt->send_buf_section_size = packet->total_data_buflen;
 
-	req_id = (ulong)skb;
 
 	if (out_channel->rescind)
 		return -ENODEV;
 
 	trace_nvsp_send_pkt(ndev, out_channel, rpkt);
 
+	rqst_id = vmbus_next_request_id(&out_channel->requestor,
+					(unsigned long)skb);
+	if (rqst_id == VMBUS_RQST_ERROR) {
+		ret = -EAGAIN;
+		goto ret_check;
+	}
+
 	if (packet->page_buf_cnt) {
 		if (packet->cp_partial)
 			pb += packet->rmsg_pgcnt;
@@ -852,14 +897,15 @@ static inline int netvsc_send_pkt(
 		ret = vmbus_sendpacket_pagebuffer(out_channel,
 						  pb, packet->page_buf_cnt,
 						  &nvmsg, sizeof(nvmsg),
-						  req_id);
+						  rqst_id);
 	} else {
 		ret = vmbus_sendpacket(out_channel,
 				       &nvmsg, sizeof(nvmsg),
-				       req_id, VM_PKT_DATA_INBAND,
+				       rqst_id, VM_PKT_DATA_INBAND,
 				       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 	}
 
+ret_check:
 	if (ret == 0) {
 		atomic_inc_return(&nvchan->queue_sends);
 
@@ -868,9 +914,13 @@ static inline int netvsc_send_pkt(
 			ndev_ctx->eth_stats.stop_queue++;
 		}
 	} else if (ret == -EAGAIN) {
+		/* Reclaim request ID to avoid leak of IDs */
+		vmbus_request_addr(&out_channel->requestor, rqst_id);
 		netif_tx_stop_queue(txq);
 		ndev_ctx->eth_stats.stop_queue++;
 	} else {
+		/* Reclaim request ID to avoid leak of IDs */
+		vmbus_request_addr(&out_channel->requestor, rqst_id);
 		netdev_err(ndev,
 			   "Unable to send packet pages %u len %u, ret %d\n",
 			   packet->page_buf_cnt, packet->total_data_buflen,
@@ -1422,6 +1472,7 @@ 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 b81ceba38218..10489ba44a09 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1114,6 +1114,7 @@ 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 c509d20ab7db..d8194924983d 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -730,6 +730,7 @@ struct vmbus_requestor {
 };
 
 #define VMBUS_RQST_ERROR U64_MAX
+#define VMBUS_RQST_ID_NO_RESPONSE (U64_MAX - 1)
 
 struct vmbus_device {
 	u16  dev_type;
-- 
2.25.1


  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-29 20:02 [PATCH v2 0/3] Drivers: hv: vmbus: vmbus_requestor data structure " Andres Beltran
2020-06-29 20:02 ` [PATCH v2 1/3] Drivers: hv: vmbus: Add " Andres Beltran
2020-06-29 20:46   ` Wei Liu
2020-06-29 21:51     ` Andres Beltran
2020-06-29 21:56       ` Michael Kelley
2020-06-29 22:09         ` Andres Beltran
2020-06-29 22:15         ` Wei Liu
2020-06-29 22:20       ` Wei Liu
2020-06-29 23:45         ` Andres Beltran
2020-06-30 10:09           ` Wei Liu
2020-06-30 10:17             ` Wei Liu
2020-06-30 10:48               ` Wei Liu
2020-06-29 20:02 ` [PATCH v2 2/3] scsi: storvsc: Use vmbus_requestor to generate transaction IDs " Andres Beltran
2020-06-29 20:02 ` Andres Beltran [this message]
2020-06-29 21:33   ` [PATCH v2 3/3] hv_netvsc: " Haiyang Zhang
2020-06-29 22:26     ` Wei Liu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200629200227.1518784-4-lkmlabelt@gmail.com \
    --to=lkmlabelt@gmail.com \
    --cc=davem@davemloft.net \
    --cc=haiyangz@microsoft.com \
    --cc=kuba@kernel.org \
    --cc=kys@microsoft.com \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mikelley@microsoft.com \
    --cc=netdev@vger.kernel.org \
    --cc=parri.andrea@gmail.com \
    --cc=sthemmin@microsoft.com \
    --cc=t-mabelt@microsoft.com \
    --cc=wei.liu@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-HyperV Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-hyperv/0 linux-hyperv/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-hyperv linux-hyperv/ https://lore.kernel.org/linux-hyperv \
		linux-hyperv@vger.kernel.org
	public-inbox-index linux-hyperv

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-hyperv


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git