From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Hongyan Xu <getshell@seu.edu.cn>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.12 1135/1376] ACPI: scan: fix bus ID cleanup on device_add() failures
Date: Sat, 12 Sep 2026 08:59:21 +0200
Message-ID: <20260912065632.857778482@linuxfoundation.org>
In-Reply-To: <20260912065607.535295758@linuxfoundation.org>
References: <20260912065607.535295758@linuxfoundation.org>
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6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hongyan Xu <getshell@seu.edu.cn>

[ Upstream commit a414485ebc2aa50907d0ce97cde2b1a353696897 ]

When device_add() fails after acpi_device_set_name() has allocated an
instance ID and a new acpi_device_bus_id has been linked into
acpi_bus_id_list, the rollback path only removes wakeup_list and
detaches the ACPI handle data.

That leaves the bus-ID bookkeeping behind and keeps the allocated
instance number consumed.

Move the bus-ID cleanup and wakeup-list removal into a single helper.

Use it from both the normal device teardown path and the device_add()
rollback path. The wakeup list node is initialized before registration,
so it can be deleted without checking whether the device is wakeup-
capable like in the original teardown path.

Fixes: d783156ea384 ("ACPI / scan: Define non-empty device removal handler")
Signed-off-by: Hongyan Xu <getshell@seu.edu.cn>
[ rjw: Rename acpi_device_del_list() to acpi_device_cleanup() ]
[ rjw: Subject and changelog edits ]
Link: https://patch.msgid.link/20260808085943.526-1-getshell@seu.edu.cn
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/acpi/scan.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 4b9c81fbdc3bb..42f0840212e87 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -521,12 +521,10 @@ static void acpi_device_release(struct device *dev)
 	kfree(acpi_dev);
 }
 
-static void acpi_device_del(struct acpi_device *device)
+static void acpi_device_cleanup(struct acpi_device *device)
 {
 	struct acpi_device_bus_id *acpi_device_bus_id;
 
-	mutex_lock(&acpi_device_lock);
-
 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
 		if (!strcmp(acpi_device_bus_id->bus_id,
 			    acpi_device_hid(device))) {
@@ -541,6 +539,13 @@ static void acpi_device_del(struct acpi_device *device)
 		}
 
 	list_del(&device->wakeup_list);
+}
+
+static void acpi_device_del(struct acpi_device *device)
+{
+	mutex_lock(&acpi_device_lock);
+
+	acpi_device_cleanup(device);
 
 	mutex_unlock(&acpi_device_lock);
 
@@ -803,7 +808,7 @@ int acpi_device_add(struct acpi_device *device)
 err:
 	mutex_lock(&acpi_device_lock);
 
-	list_del(&device->wakeup_list);
+	acpi_device_cleanup(device);
 
 err_unlock:
 	mutex_unlock(&acpi_device_lock);
-- 
2.53.0