Commit d0ef6ece authored Mar 06, 2017 by Johan Hovold Committed by Greg Kroah-Hartman Mar 18, 2017

USB: serial: io_ti: fix information leak in completion handler



commit 654b404f2a222f918af9b0cd18ad469d0c941a8e upstream.

Add missing sanity check to the bulk-in completion handler to avoid an
integer underflow that can be triggered by a malicious device.

This avoids leaking 128 kB of memory content from after the URB transfer
buffer to user space.

Fixes: 8c209e67 ("USB: make actual_length in struct urb field u32")
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 449b0bb2

drivers/usb/serial/io_ti.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1761,7 +1761,7 @@ static void edge_bulk_in_callback(struct urb *urb)

		port_number = edge_port->port->port_number;

		if (edge_port->lsr_event) {
		if (urb->actual_length > 0 && edge_port->lsr_event) {
		edge_port->lsr_event = 0;
		dev_dbg(dev, "%s ===== Port %u LSR Status = %02x, Data = %02x ======\n",
		__func__, port_number, edge_port->lsr_mask, *data);