[ALSA] rawmidi: protect against invalid device number in snd_rawmidi_info_select()

Modules: RawMidi Midlevel

In snd_rawmidi_info_select(), check that the device identified by the
passed device number actually exists.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index 7a86a9a08a15..d703545cae8a 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -573,6 +573,8 @@ int snd_rawmidi_info_select(struct snd_card *card, struct snd_rawmidi_info *info
         if (info->device >= SNDRV_RAWMIDI_DEVICES)
                 return -ENXIO;
         rmidi = snd_rawmidi_devices[card->number * SNDRV_RAWMIDI_DEVICES + info->device];
+        if (!rmidi)
+                return -ENXIO;
         if (info->stream < 0 || info->stream > 1)
                 return -EINVAL;
         pstr = &rmidi->streams[info->stream];