patch "USB: usbtmc: fix probe error path" added to usb-linus

patch "USB: usbtmc: fix probe error path" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    USB: usbtmc: fix probe error path

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 2e47c53503eb9faff42b3cfa144a833344dd1f89 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Tue, 14 Mar 2017 17:55:46 +0100
Subject: USB: usbtmc: fix probe error path

Make sure to initialise the return value to avoid having allocation
failures going unnoticed when allocating interrupt-endpoint resources.

This prevents use-after-free or worse when the device is later unbound.

Fixes: dbf3e7f654c0 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation.")
Cc: stable <stable@vger.kernel.org>     # 4.6
Cc: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/class/usbtmc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 5e3446db4513..8fb309a0ff6b 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -1476,8 +1476,10 @@ static int usbtmc_probe(struct usb_interface *intf,
 	if (data->iin_ep_present) {
 		/* allocate int urb */
 		data->iin_urb = usb_alloc_urb(0, GFP_KERNEL);
-		if (!data->iin_urb)
+		if (!data->iin_urb) {
+			retcode = -ENOMEM;
 			goto error_register;
+		}
 
 		/* Protect interrupt in endpoint data until iin_urb is freed */
 		kref_get(&data->kref);
@@ -1485,8 +1487,10 @@ static int usbtmc_probe(struct usb_interface *intf,
 		/* allocate buffer for interrupt in */
 		data->iin_buffer = kmalloc(data->iin_wMaxPacketSize,
 					GFP_KERNEL);
-		if (!data->iin_buffer)
+		if (!data->iin_buffer) {
+			retcode = -ENOMEM;
 			goto error_register;
+		}
 
 		/* fill interrupt urb */
 		usb_fill_int_urb(data->iin_urb, data->usb_dev,
-- 
2.12.0