4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nikita Kiryushin <kiryushin@xxxxxxxx>
[ 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: 9661e92c10a9 ("acpi: tie ACPI backlight devices to PCI devices if possible")
Signed-off-by: Nikita Kiryushin <kiryushin@xxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/acpi/acpi_video.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c
index eb7fca6f9444..c22297cce288 100644
--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -1797,12 +1797,12 @@ 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));
--
2.43.0
