From 04501c718370434109b14b5d42ad252eab687cd4 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Thu, 6 Jul 2017 16:06:32 +0100 Subject: [PATCH] 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 Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- drivers/usb/storage/isd200.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/usb/storage/isd200.c b/drivers/usb/storage/isd200.c index ffc4193e9505..36f18b55f2c9 100644 --- a/drivers/usb/storage/isd200.c +++ b/drivers/usb/storage/isd200.c @@ -1522,8 +1522,11 @@ 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) { US_DEBUGP("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 */ -- 2.39.2