[PATCH v1 03/17] efi/dev-path-parser: Switch to use acpi_bus_get_primary_device()

[Rafael J. Wysocki]

From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>

Replace acpi_get_first_physical_node() that is slated for removal
with acpi_bus_get_primary_device() that takes a reference to the
device it is about to return.

This addresses a potential use-after-free that may occur if the
device returned by acpi_get_first_physical_node() is removed right
after dropping its ACPI companion's physical_node_lock in that
function.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
 drivers/firmware/efi/dev-path-parser.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/dev-path-parser.c b/drivers/firmware/efi/dev-path-parser.c
index 13ea141c0def..e0f864cbaa8c 100644
--- a/drivers/firmware/efi/dev-path-parser.c
+++ b/drivers/firmware/efi/dev-path-parser.c
@@ -37,9 +37,9 @@ static long __init parse_acpi_path(const struct efi_dev_path *node,
 	if (!adev)
 		return -ENODEV;
 
-	phys_dev = acpi_get_first_physical_node(adev);
+	phys_dev = acpi_bus_get_primary_device(adev);
 	if (phys_dev) {
-		*child = get_device(phys_dev);
+		*child = phys_dev;
 		acpi_dev_put(adev);
 	} else
 		*child = &adev->dev;
-- 
2.51.0