[PATCH] sound/oss/opl3: validate voice and channel indexes

From: Dan Rosenberg
Date: Wed Mar 23 2011 - 11:43:14 EST


User-controllable indexes for voice and channel values may cause reading
and writing beyond the bounds of their respective arrays, leading to
potentially exploitable memory corruption. Validate these indexes.

Signed-off-by: Dan Rosenberg <drosenberg@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxx
---
sound/oss/opl3.c | 15 +++++++++++++--
1 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/sound/oss/opl3.c b/sound/oss/opl3.c
index 938c48c..e9d443e 100644
--- a/sound/oss/opl3.c
+++ b/sound/oss/opl3.c
@@ -849,6 +849,10 @@ static int opl3_load_patch(int dev, int format, const char __user *addr,

static void opl3_panning(int dev, int voice, int value)
{
+
+ if (voice < 0 || voice >= devc->nr_voice)
+ return;
+
devc->voc[voice].panning = value;
}

@@ -1066,8 +1070,15 @@ static int opl3_alloc_voice(int dev, int chn, int note, struct voice_alloc_info

static void opl3_setup_voice(int dev, int voice, int chn)
{
- struct channel_info *info =
- &synth_devs[dev]->chn_info[chn];
+ struct channel_info *info;
+
+ if (voice < 0 || voice >= devc->nr_voice)
+ return;
+
+ if (chn < 0 || chn > 15)
+ return;
+
+ info = &synth_devs[dev]->chn_info[chn];

opl3_set_instr(dev, voice, info->pgm_num);




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