ALSA: hda - Fix possible races in HDMI driver

commit cbbaa603a03cc46681e24d6b2804b62fde95a2af upstream.

Some per_pin fields and ELD contents might be changed dynamically in
multiple ways where the concurrent accesses are still opened in the
current code.  This patch fixes such possible races by using eld->lock
in appropriate places.

Reported-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 37da6fb999f2816cb11ffa28fa0df6bb32a51a96..78338b9c6e9ad26d3d0dc615577adbab293ea949 100644 (file)
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1355,6 +1355,7 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
        bool update_eld = false;
        bool eld_changed = false;
 
+       mutex_lock(&pin_eld->lock);
        pin_eld->monitor_present = !!(present & AC_PINSENSE_PRESENCE);
        if (pin_eld->monitor_present)
                eld->eld_valid  = !!(present & AC_PINSENSE_ELDV);
@@ -1384,11 +1385,10 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
                        queue_delayed_work(codec->bus->workq,
                                           &per_pin->work,
                                           msecs_to_jiffies(300));
-                       return;
+                       goto unlock;
                }
        }
 
-       mutex_lock(&pin_eld->lock);
        if (pin_eld->eld_valid && !eld->eld_valid) {
                update_eld = true;
                eld_changed = true;
@@ -1413,12 +1413,13 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
                        hdmi_setup_audio_infoframe(codec, per_pin,
                                                   per_pin->non_pcm);
        }
-       mutex_unlock(&pin_eld->lock);
 
        if (eld_changed)
                snd_ctl_notify(codec->bus->card,
                               SNDRV_CTL_EVENT_MASK_VALUE | SNDRV_CTL_EVENT_MASK_INFO,
                               &per_pin->eld_ctl->id);
+ unlock:
+       mutex_unlock(&pin_eld->lock);
 }
 
 static void hdmi_repoll_eld(struct work_struct *work)
@@ -1590,10 +1591,12 @@ static int generic_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
        int pinctl;
 
        non_pcm = check_non_pcm_per_cvt(codec, cvt_nid);
+       mutex_lock(&per_pin->sink_eld.lock);
        per_pin->channels = substream->runtime->channels;
        per_pin->setup = true;
 
        hdmi_setup_audio_infoframe(codec, per_pin, non_pcm);
+       mutex_unlock(&per_pin->sink_eld.lock);
 
        if (spec->dyn_pin_out) {
                pinctl = snd_hda_codec_read(codec, pin_nid, 0,
@@ -1648,11 +1651,14 @@ static int hdmi_pcm_close(struct hda_pcm_stream *hinfo,
                }
 
                snd_hda_spdif_ctls_unassign(codec, pin_idx);
+
+               mutex_lock(&per_pin->sink_eld.lock);
                per_pin->chmap_set = false;
                memset(per_pin->chmap, 0, sizeof(per_pin->chmap));
 
                per_pin->setup = false;
                per_pin->channels = 0;
+               mutex_unlock(&per_pin->sink_eld.lock);
        }
 
        return 0;
@@ -1781,10 +1787,12 @@ static int hdmi_chmap_ctl_put(struct snd_kcontrol *kcontrol,
        ca = hdmi_manual_channel_allocation(ARRAY_SIZE(chmap), chmap);
        if (ca < 0)
                return -EINVAL;
+       mutex_lock(&per_pin->sink_eld.lock);
        per_pin->chmap_set = true;
        memcpy(per_pin->chmap, chmap, sizeof(chmap));
        if (prepared)
                hdmi_setup_audio_infoframe(codec, per_pin, per_pin->non_pcm);
+       mutex_unlock(&per_pin->sink_eld.lock);
 
        return 0;
 }