This is a note to let you know that I've just added the patch titled
drm/i915: Fix invalid access to ACPI _DSM objects
to the 5.4-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:
drm-i915-fix-invalid-access-to-acpi-_dsm-objects.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b6a37a93c9ac3900987c79b726d0bb3699d8db4e Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@xxxxxxx>
Date: Fri, 2 Apr 2021 10:23:17 +0200
Subject: drm/i915: Fix invalid access to ACPI _DSM objects
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From: Takashi Iwai <tiwai@xxxxxxx>
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@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20210402082317.871-1-tiwai@xxxxxxx
(cherry picked from commit 337d7a1621c7f02af867229990ac67c97da1b53a)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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",
Patches currently in stable-queue which might be from tiwai@xxxxxxx are
queue-5.4/alsa-hda-realtek-fix-speaker-amp-setup-on-acer-aspire-e1.patch
queue-5.4/drm-i915-fix-invalid-access-to-acpi-_dsm-objects.patch
queue-5.4/alsa-aloop-fix-initialization-of-controls.patch
