Commit 446230f5 authored Jul 06, 2017 by Colin Ian King Committed by Greg Kroah-Hartman Jul 17, 2017

usb: storage: return on error to avoid a null pointer dereference



When us->extra is null the driver is not initialized, however, a
later call to osd200_scsi_to_ata is made that dereferences
us->extra, causing a null pointer dereference.  The code
currently detects and reports that the driver is not initialized;
add a return to avoid the subsequent dereference issue in this
check.

Thanks to Alan Stern for pointing out that srb->result needs setting
to DID_ERROR << 16

Detected by CoverityScan, CID#100308 ("Dereference after null check")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 86be7f7b

drivers/usb/storage/isd200.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -1529,8 +1529,11 @@ static void isd200_ata_command(struct scsi_cmnd srb, struct us_data us)

		/* Make sure driver was initialized */

		if (us->extra == NULL)
		if (us->extra == NULL) {
		usb_stor_dbg(us, "ERROR Driver not initialized\n");
		srb->result = DID_ERROR << 16;
		return;
		}

		scsi_set_resid(srb, 0);
		/* scsi_bufflen might change in protocol translation to ata */