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authorAndres Beltran <lkmlabelt@gmail.com>2020-07-06 12:09:28 -0400
committerMartin K. Petersen <martin.petersen@oracle.com>2020-07-08 01:34:08 -0400
commit0a76566595bfb242a7f4bedc77233e9194831ba3 (patch)
treef318acab28cedd0c68609e192d784b74f3fad747
parentscsi: advansys: docs: Eliminate duplicated word (diff)
downloadlinux-dev-0a76566595bfb242a7f4bedc77233e9194831ba3.tar.xz
linux-dev-0a76566595bfb242a7f4bedc77233e9194831ba3.zip
scsi: storvsc: Add validation for untrusted Hyper-V values
For additional robustness in the face of Hyper-V errors or malicious behavior, validate all values that originate from packets that Hyper-V has sent to the guest. Ensure that invalid values cannot cause data being copied out of the bounds of the source buffer when calling memcpy. Ensure that outgoing packets do not have any leftover guest memory that has not been zeroed out. Link: https://lore.kernel.org/r/20200706160928.53049-1-lkmlabelt@gmail.com Cc: James E.J. Bottomley <jejb@linux.ibm.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: linux-scsi@vger.kernel.org Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andres Beltran <lkmlabelt@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--drivers/scsi/storvsc_drv.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 7b686268ad19..5c9f6b761fd6 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1100,6 +1100,10 @@ static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
data_transfer_length = 0;
}
+ /* Validate data_transfer_length (from Hyper-V) */
+ if (data_transfer_length > cmd_request->payload->range.len)
+ data_transfer_length = cmd_request->payload->range.len;
+
scsi_set_resid(scmnd,
cmd_request->payload->range.len - data_transfer_length);
@@ -1140,6 +1144,11 @@ static void storvsc_on_io_completion(struct storvsc_device *stor_device,
/* Copy over the status...etc */
stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
+
+ /* Validate sense_info_length (from Hyper-V) */
+ if (vstor_packet->vm_srb.sense_info_length > sense_buffer_size)
+ vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
+
stor_pkt->vm_srb.sense_info_length =
vstor_packet->vm_srb.sense_info_length;
@@ -1565,6 +1574,7 @@ static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
request = &stor_device->reset_request;
vstor_packet = &request->vstor_packet;
+ memset(vstor_packet, 0, sizeof(struct vstor_packet));
init_completion(&request->wait_event);
@@ -1668,6 +1678,7 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
/* Setup the cmd request */
cmd_request->cmd = scmnd;
+ memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
vm_srb = &cmd_request->vstor_packet.vm_srb;
vm_srb->win8_extension.time_out_value = 60;