[009/105] sound/oss/opl3: validate voice and channel indexes

Greg KH
2011-04-12T14:37:39Z

From: Dan Rosenberg <drosenberg@vsecurity.com>

commit 4d00135a680727f6c3be78f8befaac009030e4df upstream.

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@vsecurity.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
sound/oss/opl3.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

--- a/sound/oss/opl3.c
+++ b/sound/oss/opl3.c
@@ -849,6 +849,10 @@ static int opl3_load_patch(int dev, int

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

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);