USB: usblp: fix use-after-free on disconnect

A recent commit addressing a runtime PM use-count regression, introduced
a use-after-free by not making sure we held a reference to the struct
usb_interface for the lifetime of the driver data.

Fixes: 9a31535859 ("USB: usblp: fix runtime PM after driver unbind")
Cc: stable <stable@vger.kernel.org>
Reported-by: syzbot+cd24df4d075c319ebfc5@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191015175522.18490-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2019-10-15 19:55:22 +02:00 committed by Greg Kroah-Hartman
parent b987b66ac3
commit 7a75919797

View File

@ -445,6 +445,7 @@ static void usblp_cleanup(struct usblp *usblp)
kfree(usblp->readbuf);
kfree(usblp->device_id_string);
kfree(usblp->statusbuf);
usb_put_intf(usblp->intf);
kfree(usblp);
}
@ -1113,7 +1114,7 @@ static int usblp_probe(struct usb_interface *intf,
init_waitqueue_head(&usblp->wwait);
init_usb_anchor(&usblp->urbs);
usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
usblp->intf = intf;
usblp->intf = usb_get_intf(intf);
/* Malloc device ID string buffer to the largest expected length,
* since we can re-query it on an ioctl and a dynamic string
@ -1198,6 +1199,7 @@ static int usblp_probe(struct usb_interface *intf,
kfree(usblp->readbuf);
kfree(usblp->statusbuf);
kfree(usblp->device_id_string);
usb_put_intf(usblp->intf);
kfree(usblp);
abort_ret:
return retval;