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

[ Upstream commit ccd45faf4973746c4f30ea41eec864e5cf191099 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Nikita Kiryushin 2023-11-09 16:49:25 +03:00 committed by Greg Kroah-Hartman
parent f5ea2cf3bb
commit 1e3a2b9b40

View File

@ -1784,12 +1784,12 @@ static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
return;
count++;
acpi_get_parent(device->dev->handle, &acpi_parent);
pdev = acpi_get_pci_dev(acpi_parent);
if (pdev) {
parent = &pdev->dev;
pci_dev_put(pdev);
if (ACPI_SUCCESS(acpi_get_parent(device->dev->handle, &acpi_parent))) {
pdev = acpi_get_pci_dev(acpi_parent);
if (pdev) {
parent = &pdev->dev;
pci_dev_put(pdev);
}
}
memset(&props, 0, sizeof(struct backlight_properties));