Commit 453de21c authored by Andres Beltran's avatar Andres Beltran Committed by Wei Liu
Browse files

scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening 



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: default avatarAndres Beltran <lkmlabelt@gmail.com>
Co-developed-by: default avatarAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: default avatarAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Link: https://lore.kernel.org/r/20201109100402.8946-3-parri.andrea@gmail.com


Acked-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: default avatarWei Liu <wei.liu@kernel.org>
Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
parent e8b7db38

drivers/scsi/storvsc_drv.c

+23 −3
Original line number Diff line number Diff line
@@ -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;

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