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authorDan Carpenter <dan.carpenter@oracle.com>2013-03-04 15:19:18 +0300
committerTakashi Iwai <tiwai@suse.de>2013-03-04 16:39:50 +0100
commit85c50a5899b23f4f893b0898b286023157b98376 (patch)
tree4b47c49fc31685ca10b7f48ed6a75b64703b7694 /sound
parent6dbe51c251a327e012439c4772097a13df43c5b8 (diff)
downloadvexpress-lsk-85c50a5899b23f4f893b0898b286023157b98376.tar.gz
ALSA: seq: seq_oss_event: missing range checks
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@oracle.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
-rw-r--r--sound/core/seq/oss/seq_oss_event.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/sound/core/seq/oss/seq_oss_event.c b/sound/core/seq/oss/seq_oss_event.c
index 066f5f3e3f4..c3908862bc8 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) {