2011-03-23 15:43:09

by Dan Rosenberg

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

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 <[email protected]>
Cc: [email protected]
---
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);

2011-03-23 22:04:31

by Takashi Iwai

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

At Wed, 23 Mar 2011 11:42:57 -0400,
Dan Rosenberg wrote:
>
> 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 <[email protected]>
> Cc: [email protected]

Applied now. Thanks.


Takashi


> ---
> 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);
>
>
>
>