From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Thu, 5 Mar 2015 17:49:06 +0000 (+0300)
Subject: ALSA: opl3: small array underflow
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d124380674b58f62d0ef974630d74d67bb8afeb0;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

ALSA: opl3: small array underflow

There is a missing lower bound check on "pitchbend" so it means we can
read up to 6 elements before the start of the opl3_note_table[] array.

Thanks to Clemens Ladisch for his help with this patch.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/sound/drivers/opl3/opl3_midi.c b/sound/drivers/opl3/opl3_midi.c
index f62780ed64ad..7821b07415a7 100644
--- a/sound/drivers/opl3/opl3_midi.c
+++ b/sound/drivers/opl3/opl3_midi.c
@@ -105,6 +105,8 @@ static void snd_opl3_calc_pitch(unsigned char *fnum, unsigned char *blocknum,
 		int pitchbend = chan->midi_pitchbend;
 		int segment;
 
+		if (pitchbend < -0x2000)
+			pitchbend = -0x2000;
 		if (pitchbend > 0x1FFF)
 			pitchbend = 0x1FFF;