This is a note to let you know that I've just added the patch titled ACPI: processor: idle: Check acpi_fetch_acpi_dev() return value to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: acpi-processor-idle-check-acpi_fetch_acpi_dev-return.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ff313635dc94f2acffb35d3655d24d2e071f1e2b Author: Li Zhong <floridsleeves@xxxxxxxxx> Date: Fri Sep 2 00:37:30 2022 -0700 ACPI: processor: idle: Check acpi_fetch_acpi_dev() return value [ Upstream commit 2437513a814b3e93bd02879740a8a06e52e2cf7d ] 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@xxxxxxxxx> [ rjw: Subject and changelog edits, added empty line after if () ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index acfabfe07c4f..fc5b5b2c9e81 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1134,6 +1134,9 @@ 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))