brain-hackers_pepepper-mirror
/
linux-brain
mirror of https://github.com/brain-hackers/linux-brain.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

drm/i915: Fix invalid access to ACPI _DSM objects 

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@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.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@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Takashi Iwai 2021-04-02 10:23:17 +02:00 committed by Greg Kroah-Hartman
parent 0e8f850e26
commit c2b3cf2c70
1 changed files with 20 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/gpu/drm/i915/display/intel_acpi.c
View File

@ -83,13 +83,31 @@ static void intel_dsm_platform_mux_info(acpi_handle dhandle)
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",