From 78a18fec5258c8df9435399a1ea022d73d3eceb9 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 15 Jan 2021 22:57:52 +0100
Subject: [PATCH] ACPI: scan: Make acpi_bus_get_device() clear return pointer on error
Git-commit: 78a18fec5258c8df9435399a1ea022d73d3eceb9
Patch-mainline: v5.11-rc5
References: git-fixes
Set the acpi_device pointer which acpi_bus_get_device() returns-by-
reference to NULL on errors.
We've recently had 2 cases where callers of acpi_bus_get_device()
did not properly error check the return value, so set the returned-
by-reference acpi_device pointer to NULL, because at least some
callers of acpi_bus_get_device() expect that to be done on errors.
[ rjw: This issue was exposed by commit 71da201f38df ("ACPI: scan:
Defer enumeration of devices with _DEP lists") which caused it to
be much more likely to occur on some systems, but the real defect
had been introduced by an earlier commit. ]
Fixes: 40e7fcb19293 ("ACPI: Add _DEP support to fix battery issue on Asus T100TA")
Fixes: bcfcd409d4db ("usb: split code locating ACPI companion into port and device")
Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Diagnosed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: All applicable <stable@vger.kernel.org>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/acpi/scan.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 58ff36340cd7..1db063b02f63 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -586,6 +586,8 @@ static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
if (!device)
return -EINVAL;
+ *device = NULL;
+
status = acpi_get_data_full(handle, acpi_scan_drop_device,
(void **)device, callback);
if (ACPI_FAILURE(status) || !*device) {
--
2.26.2