This is a note to let you know that I've just added the patch titled
usb: storage: return on error to avoid a null pointer dereference
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 446230f52a5bef593554510302465eabab45a372 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Date: Thu, 6 Jul 2017 16:06:32 +0100
Subject: 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@xxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 fba4005dd737..6a7720e66595 100644
--- a/drivers/usb/storage/isd200.c
+++ b/drivers/usb/storage/isd200.c
@@ -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 */
--
2.13.3