[PATCH AUTOSEL 5.15 33/43] ACPI: bus: Bail out if acpi_kobj registration fails

[Sasha Levin <sashal@kernel.org>]

From: Armin Wolf <W_Armin@gmx.de>

[ Upstream commit 94a370fc8def6038dbc02199db9584b0b3690f1a ]

The ACPI sysfs code will fail to initialize if acpi_kobj is NULL,
together with some ACPI drivers.

Follow the other firmware subsystems and bail out if the kobject
cannot be registered.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://patch.msgid.link/20250518185111.3560-2-W_Armin@gmx.de
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

**YES** This commit should be backported to stable kernel trees. Here's
the detailed analysis: **Bug Fix Nature**: The commit fixes a real bug
where ACPI initialization continues silently even when `acpi_kobj`
registration fails. This creates an inconsistent system state where ACPI
sysfs functionality and some drivers that depend on `acpi_kobj` will
fail later without clear indication of the root cause. **Code Change
Analysis**: - Changes `pr_debug()` to `pr_err()` for better visibility
of the failure - Returns `-ENOMEM` immediately when
`kobject_create_and_add()` fails instead of continuing - The existing
`kobject_put(acpi_kobj)` cleanup in the error path after
`acpi_bus_init()` is already present **Comparison with Similar
Commits**: This follows the exact pattern of Similar Commit #1 (Status:
YES) which added `kobject_put()` cleanup. Both commits address resource
management issues in the same function (`acpi_init`) and represent
important bugfixes with minimal risk. **Risk Assessment**: - Very low
risk - only affects the error path when kobject creation fails - Early
failure is better than silent failure leading to confusing symptoms
later - Change is contained to a single function with clear error
handling - Consistent with how other firmware subsystems handle kobject
registration failures **Stable Tree Criteria Met**: - Fixes important
bug affecting system reliability - Minimal and contained change - No
architectural modifications - Clear improvement in error handling and
debugging The commit addresses a legitimate reliability issue where ACPI
would continue initialization with a NULL `acpi_kobj`, leading to
failures in dependent subsystems that would be harder to diagnose than
an early, clear failure.

 drivers/acpi/bus.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 9bc5bc5bc359b..ea63b8f272892 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -1335,8 +1335,10 @@ static int __init acpi_init(void)
 	}
 
 	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
-	if (!acpi_kobj)
-		pr_debug("%s: kset create error\n", __func__);
+	if (!acpi_kobj) {
+		pr_err("Failed to register kobject\n");
+		return -ENOMEM;
+	}
 
 	init_prmt();
 	result = acpi_bus_init();
-- 
2.39.5