patch "USB: yurex: Fix protection fault after device removal" added to usb-linus

patch "USB: yurex: Fix protection fault after device removal" added to usb-linus

[gregkh]

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

    USB: yurex: Fix protection fault after device removal

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 ef61eb43ada6c1d6b94668f0f514e4c268093ff3 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Tue, 23 Apr 2019 14:48:29 -0400
Subject: USB: yurex: Fix protection fault after device removal

The syzkaller USB fuzzer found a general-protection-fault bug in the
yurex driver.  The fault occurs when a device has been unplugged; the
driver's interrupt-URB handler logs an error message referring to the
device by name, after the device has been unregistered and its name
deallocated.

This problem is caused by the fact that the interrupt URB isn't
cancelled until the driver's private data structure is released, which
can happen long after the device is gone.  The cure is to make sure
that the interrupt URB is killed before yurex_disconnect() returns;
this is exactly the sort of thing that usb_poison_urb() was meant for.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: syzbot+2eb9121678bdb36e6d57@syzkaller.appspotmail.com
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/misc/yurex.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c
index 6d9fd5f64903..7b306aa22d25 100644
--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -314,6 +314,7 @@ static void yurex_disconnect(struct usb_interface *interface)
 	usb_deregister_dev(interface, &yurex_class);
 
 	/* prevent more I/O from starting */
+	usb_poison_urb(dev->urb);
 	mutex_lock(&dev->io_mutex);
 	dev->interface = NULL;
 	mutex_unlock(&dev->io_mutex);
-- 
2.21.0