[PATCH v1] drivers/acpi/processor_idle: check the return value of acpi_fetch_acpi_dev()

[Li Zhong]

The return value of acpi_fetch_acpi_dev() could be NULL, which will
cause null pointer dereference if used in acpi_device_hid().

Signed-off-by: Li Zhong <floridsleeves@xxxxxxxxx>
---
 drivers/acpi/processor_idle.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 16a1663d02d4..519f8f741da3 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1117,6 +1117,8 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
 	status = acpi_get_parent(handle, &pr_ahandle);
 	while (ACPI_SUCCESS(status)) {
 		d = acpi_fetch_acpi_dev(pr_ahandle);
+		if (!d)
+			break;
 		handle = pr_ahandle;
 
 		if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
-- 
2.25.1