Patch "USB: serial: io_ti: fix information leak in completion handler" has been added to the 4.4-stable tree

Patch "USB: serial: io_ti: fix information leak in completion handler" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

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

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-serial-io_ti-fix-information-leak-in-completion-handler.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 654b404f2a222f918af9b0cd18ad469d0c941a8e Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Mon, 6 Mar 2017 17:36:40 +0100
Subject: USB: serial: io_ti: fix information leak in completion handler

From: Johan Hovold <johan@kernel.org>

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 <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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
@@ -1761,7 +1761,7 @@ static void edge_bulk_in_callback(struct
 
 	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);


Patches currently in stable-queue which might be from johan@kernel.org are

queue-4.4/usb-serial-digi_acceleport-fix-oob-event-processing.patch
queue-4.4/usb-serial-omninet-fix-reference-leaks-at-open.patch
queue-4.4/usb-serial-digi_acceleport-fix-oob-data-sanity-check.patch
queue-4.4/usb-iowarrior-fix-null-deref-in-write.patch
queue-4.4/usb-iowarrior-fix-null-deref-at-probe.patch
queue-4.4/usb-serial-io_ti-fix-null-deref-in-interrupt-callback.patch
queue-4.4/usb-serial-io_ti-fix-information-leak-in-completion-handler.patch
queue-4.4/usb-serial-safe_serial-fix-information-leak-in-completion-handler.patch