All of lore.kernel.org
 help / color / mirror / Atom feed
From: Takashi Iwai <tiwai@suse.de>
To: Jani Nikula <jani.nikula@linux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: [PATCH] drm/i915: Fix invalid access to ACPI _DSM objects
Date: Fri,  2 Apr 2021 09:47:49 +0200	[thread overview]
Message-ID: <20210402074749.25957-1-tiwai@suse.de> (raw)

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.

BugLink: http://bugzilla.opensuse.org/show_bug.cgi?id=1184074
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/gpu/drm/i915/display/intel_acpi.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c
index e21fb14d5e07..492ebc0a8257 100644
--- a/drivers/gpu/drm/i915/display/intel_acpi.c
+++ b/drivers/gpu/drm/i915/display/intel_acpi.c
@@ -84,6 +84,11 @@ 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);
@@ -91,6 +96,13 @@ static void intel_dsm_platform_mux_info(acpi_handle dhandle)
 		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];
+
+		if (obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2 ||
+		    info->type != ACPI_TYPE_BUFFER || info->buffer.length < 4) {
+			DRM_DEBUG_DRIVER("Invalid object for MUX #%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",
-- 
2.26.2


WARNING: multiple messages have this Message-ID
From: Takashi Iwai <tiwai@suse.de>
To: Jani Nikula <jani.nikula@linux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: [Intel-gfx] [PATCH] drm/i915: Fix invalid access to ACPI _DSM objects
Date: Fri,  2 Apr 2021 09:47:49 +0200	[thread overview]
Message-ID: <20210402074749.25957-1-tiwai@suse.de> (raw)

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.

BugLink: http://bugzilla.opensuse.org/show_bug.cgi?id=1184074
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/gpu/drm/i915/display/intel_acpi.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c
index e21fb14d5e07..492ebc0a8257 100644
--- a/drivers/gpu/drm/i915/display/intel_acpi.c
+++ b/drivers/gpu/drm/i915/display/intel_acpi.c
@@ -84,6 +84,11 @@ 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);
@@ -91,6 +96,13 @@ static void intel_dsm_platform_mux_info(acpi_handle dhandle)
 		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];
+
+		if (obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2 ||
+		    info->type != ACPI_TYPE_BUFFER || info->buffer.length < 4) {
+			DRM_DEBUG_DRIVER("Invalid object for MUX #%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",
-- 
2.26.2

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

             reply	other threads:[~2021-04-02  7:47 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-02  7:47 Takashi Iwai [this message]
2021-04-02  7:47 ` [Intel-gfx] " Takashi Iwai
2021-04-02  8:06 ` [Intel-gfx] ✗ Fi.CI.DOCS: warning for " Patchwork
2021-04-02  8:22 ` [PATCH] " Takashi Iwai
2021-04-02  8:22   ` [Intel-gfx] " Takashi Iwai
2021-04-02  8:30 ` [Intel-gfx] ✓ Fi.CI.BAT: success for " Patchwork

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210402074749.25957-1-tiwai@suse.de \
    --to=tiwai@suse.de \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=jani.nikula@linux.intel.com \
    --cc=joonas.lahtinen@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rodrigo.vivi@intel.com \
    --subject='Re: [PATCH] drm/i915: Fix invalid access to ACPI _DSM objects' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.