From: Thomas Weißschuh <linux@weissschuh.net>
Date: Tue, 9 Jul 2024 20:37:24 +0000 (+0200)
Subject: ACPI: sysfs: validate return type of _STR method
X-Git-Tag: v6.12-rc1~218^2~2^3~4
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4bb1e7d027413835b086aed35bc3f0713bc0f72b;p=thirdparty%2Fkernel%2Flinux.git

ACPI: sysfs: validate return type of _STR method

Only buffer objects are valid return values of _STR.

If something else is returned description_show() will access invalid
memory.

Fixes: d1efe3c324ea ("ACPI: Add new sysfs interface to export device description")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20240709-acpi-sysfs-groups-v2-1-058ab0667fa8@weissschuh.net
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c
index 23373faa35ecd..95a19e3569c83 100644
--- a/drivers/acpi/device_sysfs.c
+++ b/drivers/acpi/device_sysfs.c
@@ -540,8 +540,9 @@ int acpi_device_setup_files(struct acpi_device *dev)
 	 * If device has _STR, 'description' file is created
 	 */
 	if (acpi_has_method(dev->handle, "_STR")) {
-		status = acpi_evaluate_object(dev->handle, "_STR",
-					NULL, &buffer);
+		status = acpi_evaluate_object_typed(dev->handle, "_STR",
+						    NULL, &buffer,
+						    ACPI_TYPE_BUFFER);
 		if (ACPI_FAILURE(status))
 			buffer.pointer = NULL;
 		dev->pnp.str_obj = buffer.pointer;