ACPI: video: check for error while searching for backlight device parent

If acpi_get_parent() called in acpi_video_dev_register_backlight()
fails, for example, because acpi_ut_acquire_mutex() fails inside
acpi_get_parent), this can lead to incorrect (uninitialized)
acpi_parent handle being passed to acpi_get_pci_dev() for detecting
the parent pci device.

Check acpi_get_parent() result and set parent device only in case of success.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 9661e92c10 ("acpi: tie ACPI backlight devices to PCI devices if possible")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Nikita Kiryushin 2023-11-09 16:49:25 +03:00 • committed by Rafael J. Wysocki
commit ccd45faf49