From: Takashi Iwai <tiwai@suse.de>
Date: Thu, 22 Aug 2013 07:55:36 +0000 (+0200)
Subject: ALSA: hda - Fix NULL dereference with CONFIG_SND_DYNAMIC_MINORS=n
X-Git-Tag: firefly_0821_release~6453^2~944
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=da958137df4bcd9b2b5ea83db75f66a46c3ef46f;p=firefly-linux-kernel-4.4.55.git

ALSA: hda - Fix NULL dereference with CONFIG_SND_DYNAMIC_MINORS=n

commit 2ca320e294a738c9134a71b5029de05edbfc7aad upstream.

Without the dynamic minor assignment, HDMI codec may have less PCM
instances than the number of pins, which eventually leads to Oops.

Reported-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 496d7f21d3e5..5bc419452198 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1715,6 +1715,9 @@ static int generic_hdmi_build_controls(struct hda_codec *codec)
 		struct snd_pcm_chmap *chmap;
 		struct snd_kcontrol *kctl;
 		int i;
+
+		if (!codec->pcm_info[pin_idx].pcm)
+			break;
 		err = snd_pcm_add_chmap_ctls(codec->pcm_info[pin_idx].pcm,
 					     SNDRV_PCM_STREAM_PLAYBACK,
 					     NULL, 0, pin_idx, &chmap);