RE: [PATCH 3/3] scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()

[Michael Kelley]

From: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx> Sent: Thursday, December 17, 2020 12:33 PM
> 
> Check that the packet is of the expected size at least, don't copy data
> past the packet.
> 
> Reported-by: Saruhan Karademir <skarade@xxxxxxxxxxxxx>
> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
> Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
> Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
> Cc: linux-scsi@xxxxxxxxxxxxxxx
> ---
>  drivers/scsi/storvsc_drv.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
> index 8714355cb63e7..4b8bde2750fac 100644
> --- a/drivers/scsi/storvsc_drv.c
> +++ b/drivers/scsi/storvsc_drv.c
> @@ -1250,6 +1250,12 @@ static void storvsc_on_channel_callback(void *context)
>  		request = (struct storvsc_cmd_request *)
>  			((unsigned long)desc->trans_id);
> 
> +		if (hv_pkt_datalen(desc) < sizeof(struct vstor_packet) -
> +				stor_device->vmscsi_size_delta) {
> +			dev_err(&device->device, "Invalid packet len\n");
> +			continue;
> +		}
> +
>  		if (request == &stor_device->init_request ||
>  		    request == &stor_device->reset_request) {
>  			memcpy(&request->vstor_packet, packet,
> --
> 2.25.1

Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>