Commit 249cec18 authored Jul 06, 2017 by Colin Ian King Committed by Greg Kroah-Hartman Jul 27, 2017

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



commit 446230f52a5bef593554510302465eabab45a372 upstream.

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>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent e19d1c64

drivers/usb/storage/isd200.c

+4 −1

Original line number	Original line	Diff line number	Diff line
	@@ -1522,8 +1522,11 @@ static void isd200_ata_command(struct scsi_cmnd srb, struct us_data us)

	/* Make sure driver was initialized */		/* Make sure driver was initialized */

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

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