pve-qemu/debian/patches/extra/CVE-2016-8669-char-serial-c...

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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