4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai <tiwai@xxxxxxx> commit c2432466f583cb719b35a41e757da587d9ab1d00 upstream. We got a regression report about the HD-audio HDMI chmap, where some surround channels are reported as UNKNOWN. The git bisection pointed the culprit at the commit 9b3dc8aa3fb1 ("ALSA: hda - Register chmap obj as priv data instead of codec"). The story behind scene is like this: - While moving the code out of the legacy HDA to the HDA common place, the patch modifies the code to obtain the chmap array indirectly in a byte array, and it expands it to kctl value array. - At the latter operation, the size of the array is wrongly passed by sizeof() to the pointer. - It can be 4 on 32bit arch, thus too short for 6+ channels. (And that's the reason why it didn't hit other persons; it's 8 on 64bit arch, thus it's usually enough.) The code was further changed meanwhile, but the problem persisted. Let's fix it by correctly evaluating the array size. Fixes: 9b3dc8aa3fb1 ("ALSA: hda - Register chmap obj as priv data instead of codec") Reported-by: VDR User <user.vdr@xxxxxxxxx> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/hda/hdmi_chmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/sound/hda/hdmi_chmap.c +++ b/sound/hda/hdmi_chmap.c @@ -746,7 +746,7 @@ static int hdmi_chmap_ctl_get(struct snd memset(pcm_chmap, 0, sizeof(pcm_chmap)); chmap->ops.get_chmap(chmap->hdac, pcm_idx, pcm_chmap); - for (i = 0; i < sizeof(chmap); i++) + for (i = 0; i < ARRAY_SIZE(pcm_chmap); i++) ucontrol->value.integer.value[i] = pcm_chmap[i]; return 0;