fix #1237: include cirrus follow up fixes

[pve-qemu-kvm.git] / debian / patches / extra / CVE-2016-8669-char-serial-check-divider-value-against-baud-base.patch

From 7e0ebfd13e55a706396197437f375692bbf75d15 Mon Sep 17 00:00:00 2001
From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Wed, 12 Oct 2016 11:28:08 +0530
Subject: [PATCH 2/2] char: serial: check divider value against baud base

16550A UART device uses an oscillator to generate frequencies
(baud base), which decide communication speed. This speed could
be changed by dividing it by a divider. If the divider is
greater than the baud base, speed is set to zero, leading to a
divide by zero error. Add check to avoid it.

Reported-by: Huawei PSIRT <psirt@huawei.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/char/serial.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/char/serial.c b/hw/char/serial.c
index 3442f47..eec72b7 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -153,8 +153,9 @@ static void serial_update_parameters(SerialState *s)
     int speed, parity, data_bits, stop_bits, frame_size;
     QEMUSerialSetParams ssp;
 
-    if (s->divider == 0)
+    if (s->divider == 0 || s->divider > s->baudbase) {
         return;
+    }
 
     /* Start bit. */
     frame_size = 1;
-- 
2.1.4