At Mon, 4 Mar 2013 15:19:18 +0300,
Dan Carpenter wrote:
>
> The "dev" variable could be out of bounds. Calling
> snd_seq_oss_synth_is_valid() checks that it is is a valid device
> which has been opened. We check this inside set_note_event() so
> this function can't succeed without a valid "dev". But we need to
> do the check earlier to prevent invalid dereferences and memory
> corruption.
>
> One call tree where "dev" could be out of bounds is:
> -> snd_seq_oss_oob_user()
> -> snd_seq_oss_process_event()
> -> extended_event()
> -> note_on_event()
>
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Thanks, applied.
Takashi
>
> diff --git a/sound/core/seq/oss/seq_oss_event.c b/sound/core/seq/oss/seq_oss_event.c
> index 066f5f3..c390886 100644
> --- a/sound/core/seq/oss/seq_oss_event.c
> +++ b/sound/core/seq/oss/seq_oss_event.c
> @@ -285,7 +285,12 @@ local_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev
> static int
> note_on_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev)
> {
> - struct seq_oss_synthinfo *info = &dp->synths[dev];
> + struct seq_oss_synthinfo *info;
> +
> + if (!snd_seq_oss_synth_is_valid(dp, dev))
> + return -ENXIO;
> +
> + info = &dp->synths[dev];
> switch (info->arg.event_passing) {
> case SNDRV_SEQ_OSS_PROCESS_EVENTS:
> if (! info->ch || ch < 0 || ch >= info->nr_voices) {
> @@ -340,7 +345,12 @@ note_on_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, st
> static int
> note_off_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev)
> {
> - struct seq_oss_synthinfo *info = &dp->synths[dev];
> + struct seq_oss_synthinfo *info;
> +
> + if (!snd_seq_oss_synth_is_valid(dp, dev))
> + return -ENXIO;
> +
> + info = &dp->synths[dev];
> switch (info->arg.event_passing) {
> case SNDRV_SEQ_OSS_PROCESS_EVENTS:
> if (! info->ch || ch < 0 || ch >= info->nr_voices) {
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