linux-kernel - [PATCH 5.4 012/111] drm/i915: Fix invalid access to ACPI

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210412084004.629496834@linuxfoundation.org>
Date:   Mon, 12 Apr 2021 10:39:50 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Takashi Iwai <tiwai@...e.de>,
        Ville Syrjälä 
        <ville.syrjala@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>
Subject: [PATCH 5.4 012/111] drm/i915: Fix invalid access to ACPI _DSM objects

From: Takashi Iwai <tiwai@...e.de>

commit b6a37a93c9ac3900987c79b726d0bb3699d8db4e upstream.

intel_dsm_platform_mux_info() tries to parse the ACPI package data
from _DSM for the debug information, but it assumes the fixed format
without checking what values are stored in the elements actually.
When an unexpected value is returned from BIOS, it may lead to GPF or
NULL dereference, as reported recently.

Add the checks of the contents in the returned values and skip the
values for invalid cases.

v1->v2: Check the info contents before dereferencing, too

BugLink: http://bugzilla.opensuse.org/show_bug.cgi?id=1184074
Cc: <stable@...r.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@...e.de>
Signed-off-by: Ville Syrjälä <ville.syrjala@...ux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210402082317.871-1-tiwai@suse.de
(cherry picked from commit 337d7a1621c7f02af867229990ac67c97da1b53a)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@...el.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/gpu/drm/i915/display/intel_acpi.c |   22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/display/intel_acpi.c
+++ b/drivers/gpu/drm/i915/display/intel_acpi.c
@@ -83,13 +83,31 @@ static void intel_dsm_platform_mux_info(
 		return;
 	}
 
+	if (!pkg->package.count) {
+		DRM_DEBUG_DRIVER("no connection in _DSM\n");
+		return;
+	}
+
 	connector_count = &pkg->package.elements[0];
 	DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
 		  (unsigned long long)connector_count->integer.value);
 	for (i = 1; i < pkg->package.count; i++) {
 		union acpi_object *obj = &pkg->package.elements[i];
-		union acpi_object *connector_id = &obj->package.elements[0];
-		union acpi_object *info = &obj->package.elements[1];
+		union acpi_object *connector_id;
+		union acpi_object *info;
+
+		if (obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2) {
+			DRM_DEBUG_DRIVER("Invalid object for MUX #%d\n", i);
+			continue;
+		}
+
+		connector_id = &obj->package.elements[0];
+		info = &obj->package.elements[1];
+		if (info->type != ACPI_TYPE_BUFFER || info->buffer.length < 4) {
+			DRM_DEBUG_DRIVER("Invalid info for MUX obj #%d\n", i);
+			continue;
+		}
+
 		DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
 			  (unsigned long long)connector_id->integer.value);
 		DRM_DEBUG_DRIVER("  port id: %s\n",