[06/74] sound/oss/opl3: validate voice and channel indexes

From: Greg KH
Date: Wed Apr 13 2011 - 12:31:51 EST


2.6.32-longterm review patch. If anyone has any objections, please let us know.

------------------

From: Dan Rosenberg <drosenberg@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

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

--- a/sound/oss/opl3.c
+++ b/sound/oss/opl3.c
@@ -848,6 +848,10 @@ 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;
}

@@ -1065,8 +1069,15 @@ 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);



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