Hi Greg,
On Sat, Oct 17, 2020 at 01:21:37PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
>
> The patch below does not apply to the 4.14-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@xxxxxxxxxxxxxxx>.
Here is the backport and also f69548ffafcc ("ALSA: hda/hdmi: Use single mutex unlock in error paths")
which is only needed to make the backport easier.
This will also apply to 4.9-stable.
--
Regards
Sudip
>From 809e5730b91d8258c8fe956011ad242a98072111 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@xxxxxxx>
Date: Thu, 12 Jul 2018 23:06:51 +0200
Subject: [PATCH 1/2] ALSA: hda/hdmi: Use single mutex unlock in error paths
commit f69548ffafcc4942022f16f2f192b24143de1dba upstream
Instead of calling mutex_unlock() at each error path multiple times,
take the standard goto-and-a-single-unlock approach. This will
simplify the code and make easier to find the unbalanced mutex locks.
No functional changes, but only the code readability improvement as a
preliminary work for further changes.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
sound/pci/hda/patch_hdmi.c | 67 +++++++++++++++++++++++-----------------------
1 file changed, 33 insertions(+), 34 deletions(-)
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 75bdcede04e6..062aa118991c 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -339,13 +339,13 @@ static int hdmi_eld_ctl_info(struct snd_kcontrol *kcontrol,
if (!per_pin) {
/* no pin is bound to the pcm */
uinfo->count = 0;
- mutex_unlock(&spec->pcm_lock);
- return 0;
+ goto unlock;
}
eld = &per_pin->sink_eld;
uinfo->count = eld->eld_valid ? eld->eld_size : 0;
- mutex_unlock(&spec->pcm_lock);
+ unlock:
+ mutex_unlock(&spec->pcm_lock);
return 0;
}
@@ -357,6 +357,7 @@ static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
struct hdmi_spec_per_pin *per_pin;
struct hdmi_eld *eld;
int pcm_idx;
+ int err = 0;
pcm_idx = kcontrol->private_value;
mutex_lock(&spec->pcm_lock);
@@ -365,16 +366,15 @@ static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
/* no pin is bound to the pcm */
memset(ucontrol->value.bytes.data, 0,
ARRAY_SIZE(ucontrol->value.bytes.data));
- mutex_unlock(&spec->pcm_lock);
- return 0;
+ goto unlock;
}
- eld = &per_pin->sink_eld;
+ eld = &per_pin->sink_eld;
if (eld->eld_size > ARRAY_SIZE(ucontrol->value.bytes.data) ||
eld->eld_size > ELD_MAX_SIZE) {
- mutex_unlock(&spec->pcm_lock);
snd_BUG();
- return -EINVAL;
+ err = -EINVAL;
+ goto unlock;
}
memset(ucontrol->value.bytes.data, 0,
@@ -382,9 +382,10 @@ static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
if (eld->eld_valid)
memcpy(ucontrol->value.bytes.data, eld->eld_buffer,
eld->eld_size);
- mutex_unlock(&spec->pcm_lock);
- return 0;
+ unlock:
+ mutex_unlock(&spec->pcm_lock);
+ return err;
}
static const struct snd_kcontrol_new eld_bytes_ctl = {
@@ -1209,8 +1210,8 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
pin_idx = hinfo_to_pin_index(codec, hinfo);
if (!spec->dyn_pcm_assign) {
if (snd_BUG_ON(pin_idx < 0)) {
- mutex_unlock(&spec->pcm_lock);
- return -EINVAL;
+ err = -EINVAL;
+ goto unlock;
}
} else {
/* no pin is assigned to the PCM
@@ -1218,16 +1219,13 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
*/
if (pin_idx < 0) {
err = hdmi_pcm_open_no_pin(hinfo, codec, substream);
- mutex_unlock(&spec->pcm_lock);
- return err;
+ goto unlock;
}
}
err = hdmi_choose_cvt(codec, pin_idx, &cvt_idx);
- if (err < 0) {
- mutex_unlock(&spec->pcm_lock);
- return err;
- }
+ if (err < 0)
+ goto unlock;
per_cvt = get_cvt(spec, cvt_idx);
/* Claim converter */
@@ -1264,12 +1262,11 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
per_cvt->assigned = 0;
hinfo->nid = 0;
snd_hda_spdif_ctls_unassign(codec, pcm_idx);
- mutex_unlock(&spec->pcm_lock);
- return -ENODEV;
+ err = -ENODEV;
+ goto unlock;
}
}
- mutex_unlock(&spec->pcm_lock);
/* Store the updated parameters */
runtime->hw.channels_min = hinfo->channels_min;
runtime->hw.channels_max = hinfo->channels_max;
@@ -1278,7 +1275,9 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
snd_pcm_hw_constraint_step(substream->runtime, 0,
SNDRV_PCM_HW_PARAM_CHANNELS, 2);
- return 0;
+ unlock:
+ mutex_unlock(&spec->pcm_lock);
+ return err;
}
/*
@@ -1876,7 +1875,7 @@ static int generic_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
struct snd_pcm_runtime *runtime = substream->runtime;
bool non_pcm;
int pinctl;
- int err;
+ int err = 0;
mutex_lock(&spec->pcm_lock);
pin_idx = hinfo_to_pin_index(codec, hinfo);
@@ -1888,13 +1887,12 @@ static int generic_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
pin_cvt_fixup(codec, NULL, cvt_nid);
snd_hda_codec_setup_stream(codec, cvt_nid,
stream_tag, 0, format);
- mutex_unlock(&spec->pcm_lock);
- return 0;
+ goto unlock;
}
if (snd_BUG_ON(pin_idx < 0)) {
- mutex_unlock(&spec->pcm_lock);
- return -EINVAL;
+ err = -EINVAL;
+ goto unlock;
}
per_pin = get_pin(spec, pin_idx);
pin_nid = per_pin->pin_nid;
@@ -1933,6 +1931,7 @@ static int generic_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
/* snd_hda_set_dev_select() has been called before */
err = spec->ops.setup_stream(codec, cvt_nid, pin_nid,
stream_tag, format);
+ unlock:
mutex_unlock(&spec->pcm_lock);
return err;
}
@@ -1954,6 +1953,7 @@ static int hdmi_pcm_close(struct hda_pcm_stream *hinfo,
struct hdmi_spec_per_cvt *per_cvt;
struct hdmi_spec_per_pin *per_pin;
int pinctl;
+ int err = 0;
if (hinfo->nid) {
pcm_idx = hinfo_to_pcm_index(codec, hinfo);
@@ -1972,14 +1972,12 @@ static int hdmi_pcm_close(struct hda_pcm_stream *hinfo,
snd_hda_spdif_ctls_unassign(codec, pcm_idx);
clear_bit(pcm_idx, &spec->pcm_in_use);
pin_idx = hinfo_to_pin_index(codec, hinfo);
- if (spec->dyn_pcm_assign && pin_idx < 0) {
- mutex_unlock(&spec->pcm_lock);
- return 0;
- }
+ if (spec->dyn_pcm_assign && pin_idx < 0)
+ goto unlock;
if (snd_BUG_ON(pin_idx < 0)) {
- mutex_unlock(&spec->pcm_lock);
- return -EINVAL;
+ err = -EINVAL;
+ goto unlock;
}
per_pin = get_pin(spec, pin_idx);
@@ -1998,10 +1996,11 @@ static int hdmi_pcm_close(struct hda_pcm_stream *hinfo,
per_pin->setup = false;
per_pin->channels = 0;
mutex_unlock(&per_pin->lock);
+ unlock:
mutex_unlock(&spec->pcm_lock);
}
- return 0;
+ return err;
}
static const struct hda_pcm_ops generic_ops = {
--
2.11.0
>From 613a942e4b0013fb217ae1af9b4d70598d8aed9a Mon Sep 17 00:00:00 2001
From: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
Date: Tue, 13 Oct 2020 18:26:28 +0300
Subject: [PATCH 2/2] ALSA: hda/hdmi: fix incorrect locking in hdmi_pcm_close
commit ce1558c285f9ad04c03b46833a028230771cc0a7 upstream
A race exists between closing a PCM and update of ELD data. In
hdmi_pcm_close(), hinfo->nid value is modified without taking
spec->pcm_lock. If this happens concurrently while processing an ELD
update in hdmi_pcm_setup_pin(), converter assignment may be done
incorrectly.
This bug was found by hitting a WARN_ON in snd_hda_spdif_ctls_assign()
in a HDMI receiver connection stress test:
[2739.684569] WARNING: CPU: 5 PID: 2090 at sound/pci/hda/patch_hdmi.c:1898 check_non_pcm_per_cvt+0x41/0x50 [snd_hda_codec_hdmi]
...
[2739.684707] Call Trace:
[2739.684720] update_eld+0x121/0x5a0 [snd_hda_codec_hdmi]
[2739.684736] hdmi_present_sense+0x21e/0x3b0 [snd_hda_codec_hdmi]
[2739.684750] check_presence_and_report+0x81/0xd0 [snd_hda_codec_hdmi]
[2739.684842] intel_audio_codec_enable+0x122/0x190 [i915]
Fixes: 42b2987079ec ("ALSA: hda - hdmi playback without monitor in dynamic pcm bind mode")
Signed-off-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20201013152628.920764-1-kai.vehmanen@xxxxxxxxxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
sound/pci/hda/patch_hdmi.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 062aa118991c..21d9b7d96eb0 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1955,20 +1955,23 @@ static int hdmi_pcm_close(struct hda_pcm_stream *hinfo,
int pinctl;
int err = 0;
+ mutex_lock(&spec->pcm_lock);
if (hinfo->nid) {
pcm_idx = hinfo_to_pcm_index(codec, hinfo);
- if (snd_BUG_ON(pcm_idx < 0))
- return -EINVAL;
+ if (snd_BUG_ON(pcm_idx < 0)) {
+ err = -EINVAL;
+ goto unlock;
+ }
cvt_idx = cvt_nid_to_cvt_index(codec, hinfo->nid);
- if (snd_BUG_ON(cvt_idx < 0))
- return -EINVAL;
+ if (snd_BUG_ON(cvt_idx < 0)) {
+ err = -EINVAL;
+ goto unlock;
+ }
per_cvt = get_cvt(spec, cvt_idx);
-
snd_BUG_ON(!per_cvt->assigned);
per_cvt->assigned = 0;
hinfo->nid = 0;
- mutex_lock(&spec->pcm_lock);
snd_hda_spdif_ctls_unassign(codec, pcm_idx);
clear_bit(pcm_idx, &spec->pcm_in_use);
pin_idx = hinfo_to_pin_index(codec, hinfo);
@@ -1996,10 +1999,11 @@ static int hdmi_pcm_close(struct hda_pcm_stream *hinfo,
per_pin->setup = false;
per_pin->channels = 0;
mutex_unlock(&per_pin->lock);
- unlock:
- mutex_unlock(&spec->pcm_lock);
}
+unlock:
+ mutex_unlock(&spec->pcm_lock);
+
return err;
}
--
2.11.0
