From: Johan Hovold johan@kernel.org
commit 7a759197974894213621aa65f0571b51904733d6 upstream.
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: 9a31535859bf ("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
--- drivers/usb/class/usblp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/usb/class/usblp.c +++ b/drivers/usb/class/usblp.c @@ -445,6 +445,7 @@ static void usblp_cleanup(struct usblp * kfree(usblp->readbuf); kfree(usblp->device_id_string); kfree(usblp->statusbuf); + usb_put_intf(usblp->intf); kfree(usblp); }
@@ -1107,7 +1108,7 @@ static int usblp_probe(struct usb_interf 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 @@ -1196,6 +1197,7 @@ abort: kfree(usblp->readbuf); kfree(usblp->statusbuf); kfree(usblp->device_id_string); + usb_put_intf(usblp->intf); kfree(usblp); abort_ret: return retval;