iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

USB: yurex: Fix protection fault after device removal

Browse Source 
commit ef61eb43ada6c1d6b94668f0f514e4c268093ff3 upstream.

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>
This commit is contained in:
Alan Stern 2019-04-23 14:48:29 -04:00 committed by Greg Kroah-Hartman
parent bfa5aa541c
commit 5696fa3f42
1 changed files with 1 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/usb/misc/yurex.c
View File

@ -318,6 +318,7 @@ 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);