From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Alan Stern Subject: [PATCH 4.12 070/196] usb: storage: return on error to avoid a null pointer dereference Date: Tue, 25 Jul 2017 12:21:09 -0700 Message-Id: <20170725192050.134423595@linuxfoundation.org> In-Reply-To: <20170725192046.422343510@linuxfoundation.org> References: <20170725192046.422343510@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Colin Ian King 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 Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/isd200.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/usb/storage/isd200.c +++ b/drivers/usb/storage/isd200.c @@ -1529,8 +1529,11 @@ static void isd200_ata_command(struct sc /* 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 */