This is a note to let you know that I've just added the patch titled
ALSA: control: Fix power_ref lock order for compat code, too
to the 6.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-control-fix-power_ref-lock-order-for-compat-cod.patch
and it can be found in the queue-6.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit adeb1ecd1a787bdeb0b7f7ffd88b4a5d362c678e
Author: Takashi Iwai <tiwai@xxxxxxx>
Date: Thu Aug 8 18:31:27 2024 +0200
ALSA: control: Fix power_ref lock order for compat code, too
[ Upstream commit a1066453b5e49a28523f3ecbbfe4e06c6a29561c ]
In the previous change for swapping the power_ref and controls_rwsem
lock order, the code path for the compat layer was forgotten.
This patch covers the remaining code.
Fixes: fcc62b19104a ("ALSA: control: Take power_ref lock primarily")
Link: https://patch.msgid.link/20240808163128.20383-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/core/control_compat.c b/sound/core/control_compat.c
index 934bb945e702a..ff0031cc7dfb8 100644
--- a/sound/core/control_compat.c
+++ b/sound/core/control_compat.c
@@ -79,6 +79,7 @@ struct snd_ctl_elem_info32 {
static int snd_ctl_elem_info_compat(struct snd_ctl_file *ctl,
struct snd_ctl_elem_info32 __user *data32)
{
+ struct snd_card *card = ctl->card;
struct snd_ctl_elem_info *data __free(kfree) = NULL;
int err;
@@ -95,7 +96,11 @@ static int snd_ctl_elem_info_compat(struct snd_ctl_file *ctl,
if (get_user(data->value.enumerated.item, &data32->value.enumerated.item))
return -EFAULT;
+ err = snd_power_ref_and_wait(card);
+ if (err < 0)
+ return err;
err = snd_ctl_elem_info(ctl, data);
+ snd_power_unref(card);
if (err < 0)
return err;
/* restore info to 32bit */
@@ -175,10 +180,7 @@ static int get_ctl_type(struct snd_card *card, struct snd_ctl_elem_id *id,
if (info == NULL)
return -ENOMEM;
info->id = *id;
- err = snd_power_ref_and_wait(card);
- if (!err)
- err = kctl->info(kctl, info);
- snd_power_unref(card);
+ err = kctl->info(kctl, info);
if (err >= 0) {
err = info->type;
*countp = info->count;
@@ -275,8 +277,8 @@ static int copy_ctl_value_to_user(void __user *userdata,
return 0;
}
-static int ctl_elem_read_user(struct snd_card *card,
- void __user *userdata, void __user *valuep)
+static int __ctl_elem_read_user(struct snd_card *card,
+ void __user *userdata, void __user *valuep)
{
struct snd_ctl_elem_value *data __free(kfree) = NULL;
int err, type, count;
@@ -296,8 +298,21 @@ static int ctl_elem_read_user(struct snd_card *card,
return copy_ctl_value_to_user(userdata, valuep, data, type, count);
}
-static int ctl_elem_write_user(struct snd_ctl_file *file,
- void __user *userdata, void __user *valuep)
+static int ctl_elem_read_user(struct snd_card *card,
+ void __user *userdata, void __user *valuep)
+{
+ int err;
+
+ err = snd_power_ref_and_wait(card);
+ if (err < 0)
+ return err;
+ err = __ctl_elem_read_user(card, userdata, valuep);
+ snd_power_unref(card);
+ return err;
+}
+
+static int __ctl_elem_write_user(struct snd_ctl_file *file,
+ void __user *userdata, void __user *valuep)
{
struct snd_ctl_elem_value *data __free(kfree) = NULL;
struct snd_card *card = file->card;
@@ -318,6 +333,20 @@ static int ctl_elem_write_user(struct snd_ctl_file *file,
return copy_ctl_value_to_user(userdata, valuep, data, type, count);
}
+static int ctl_elem_write_user(struct snd_ctl_file *file,
+ void __user *userdata, void __user *valuep)
+{
+ struct snd_card *card = file->card;
+ int err;
+
+ err = snd_power_ref_and_wait(card);
+ if (err < 0)
+ return err;
+ err = __ctl_elem_write_user(file, userdata, valuep);
+ snd_power_unref(card);
+ return err;
+}
+
static int snd_ctl_elem_read_user_compat(struct snd_card *card,
struct snd_ctl_elem_value32 __user *data32)
{
