From 72bb2b96b8568a74f28e2a2c39e005583595b2c2 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 6 Mar 2017 17:36:40 +0100 Subject: 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: 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: Greg Kroah-Hartman --- drivers/usb/serial/io_ti.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c index 67d68b502a51..f1a8fdcd8674 100644 --- a/drivers/usb/serial/io_ti.c +++ b/drivers/usb/serial/io_ti.c @@ -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); -- cgit v1.2.3