From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Johan Hovold" Date: Thu, 01 Jun 2017 16:40:55 +0100 Message-ID: Subject: [PATCH 3.2 095/101] USB: serial: io_ti: fix information leak in completion handler In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2.89-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold 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: 8c209e6782ca ("USB: make actual_length in struct urb field u32") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Johan Hovold Signed-off-by: Ben Hutchings --- drivers/usb/serial/io_ti.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/usb/serial/io_ti.c +++ b/drivers/usb/serial/io_ti.c @@ -1766,7 +1766,7 @@ static void edge_bulk_in_callback(struct port_number = edge_port->port->number - edge_port->port->serial->minor; - if (edge_port->lsr_event) { + if (urb->actual_length > 0 && edge_port->lsr_event) { edge_port->lsr_event = 0; dbg("%s ===== Port %u LSR Status = %02x, Data = %02x ======", __func__, port_number, edge_port->lsr_mask, *data);