ACPI: processor: idle: Check acpi_fetch_acpi_dev() return value

commit 2437513a814b3e93bd02879740a8a06e52e2cf7d upstream.

The return value of acpi_fetch_acpi_dev() could be NULL, which would
cause a NULL pointer dereference to occur in acpi_device_hid().

Signed-off-by: Li Zhong <floridsleeves@gmail.com>
[ rjw: Subject and changelog edits, added empty line after if () ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Teddy Astie <teddy.astie@vates.tech>
Signed-off-by: Yann Sionneau <yann.sionneau@vates.tech>
Reported-by: Dillon C <dchan@dchan.tech>
Tested-by: Dillon C <dchan@dchan.tech>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 42c7bdb352d2026d0b7674e5fe366074727dcc52..949efdd1b9a18a0839438746cff23bc0c45d76c8 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1128,7 +1128,9 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
 
        status = acpi_get_parent(handle, &pr_ahandle);
        while (ACPI_SUCCESS(status)) {
-               acpi_bus_get_device(pr_ahandle, &d);
+               if (acpi_bus_get_device(pr_ahandle, &d))
+                       break;
+
                handle = pr_ahandle;
 
                if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))