From patchwork Mon Nov 27 14:37:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 13469737 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="bhhLJflG" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BBC6191 for ; Mon, 27 Nov 2023 06:37:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701095868; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Pn2QY9BkzTsBxRkgzM3InhgNVD/4YvY9FZFSMQPAJn0=; b=bhhLJflGlUpTTjEy3qL8/6PypJJv3yi/5egroWe4nM/oKaYRfFgghTCasO0zzuAVs7sT/I KvpB00oc4XYTkToUZpqB7xiCn+S15wHQStneDg7N1E1WxqI12OG5qVh6oz6b3ggp+u/iSF xnBBvJdXFvPKPdEhwio6elDMKe23rbk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-286-DO237glwNUe4j5hIC_HhZA-1; Mon, 27 Nov 2023 09:37:44 -0500 X-MC-Unique: DO237glwNUe4j5hIC_HhZA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 591AF866DCB; Mon, 27 Nov 2023 14:37:44 +0000 (UTC) Received: from x1.localdomain.com (unknown [10.39.192.45]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6639420268D2; Mon, 27 Nov 2023 14:37:43 +0000 (UTC) From: Hans de Goede To: "Rafael J . Wysocki" , Michal Wilczynski Cc: Hans de Goede , Jani Nikula , linux-acpi@vger.kernel.org, "6 . 6+" Subject: [PATCH 1/1] ACPI: video: Use acpi_video_device for cooling-dev driver data Date: Mon, 27 Nov 2023 15:37:41 +0100 Message-ID: <20231127143741.5229-2-hdegoede@redhat.com> In-Reply-To: <20231127143741.5229-1-hdegoede@redhat.com> References: <20231127143741.5229-1-hdegoede@redhat.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 The acpi_video code was storing the acpi_video_device as driver-data in the acpi_device children of the acpi_video_bus acpi_device. But the acpi_video driver only binds to the bus acpi_device. It uses, but does not bind to, the children. Since it is not the driver it should not be using the driver_data of the children's acpi_device-s. Since commit 0d16710146a1 ("ACPI: bus: Set driver_data to NULL every time .add() fails") the childen's driver_data ends up getting set to NULL after a driver fails to bind to the children leading to a NULL pointer deref in video_get_max_state when registering the cooling-dev: [ 3.148958] BUG: kernel NULL pointer dereference, address: 0000000000000090 [ 3.149015] Hardware name: Sony Corporation VPCSB2X9R/VAIO, BIOS R2087H4 06/15/2012 [ 3.149021] RIP: 0010:video_get_max_state+0x17/0x30 [video] [ 3.149105] Call Trace: [ 3.149110] [ 3.149114] ? __die+0x23/0x70 [ 3.149126] ? page_fault_oops+0x171/0x4e0 [ 3.149137] ? exc_page_fault+0x7f/0x180 [ 3.149147] ? asm_exc_page_fault+0x26/0x30 [ 3.149158] ? video_get_max_state+0x17/0x30 [video 9b6f3f0d19d7b4a0e2df17a2d8b43bc19c2ed71f] [ 3.149176] ? __pfx_video_get_max_state+0x10/0x10 [video 9b6f3f0d19d7b4a0e2df17a2d8b43bc19c2ed71f] [ 3.149192] __thermal_cooling_device_register.part.0+0xf2/0x2f0 [ 3.149205] acpi_video_bus_register_backlight.part.0.isra.0+0x414/0x570 [video 9b6f3f0d19d7b4a0e2df17a2d8b43bc19c2ed71f] [ 3.149227] acpi_video_register_backlight+0x57/0x80 [video 9b6f3f0d19d7b4a0e2df17a2d8b43bc19c2ed71f] [ 3.149245] intel_acpi_video_register+0x68/0x90 [i915 1f3a758130b32ef13d301d4f8f78c7d766d57f2a] [ 3.149669] intel_display_driver_register+0x28/0x50 [i915 1f3a758130b32ef13d301d4f8f78c7d766d57f2a] [ 3.150064] i915_driver_probe+0x790/0xb90 [i915 1f3a758130b32ef13d301d4f8f78c7d766d57f2a] [ 3.150402] local_pci_probe+0x45/0xa0 [ 3.150412] pci_device_probe+0xc1/0x260 Fix this by directly using the acpi_video_device as devdata for the cooling-device, which avoids the need to set driver-data on the children at all. Fixes: 0d16710146a1 ("ACPI: bus: Set driver_data to NULL every time .add() fails") Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9718 Cc: Michal Wilczynski Cc: 6.6+ # 6.6+ Signed-off-by: Hans de Goede --- drivers/acpi/acpi_video.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index 5eded14f8853..7cd91e85c62a 100644 --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -253,8 +253,7 @@ static const struct backlight_ops acpi_backlight_ops = { static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned long *state) { - struct acpi_device *device = cooling_dev->devdata; - struct acpi_video_device *video = acpi_driver_data(device); + struct acpi_video_device *video = cooling_dev->devdata; *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1; return 0; @@ -263,8 +262,7 @@ static int video_get_max_state(struct thermal_cooling_device *cooling_dev, static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long *state) { - struct acpi_device *device = cooling_dev->devdata; - struct acpi_video_device *video = acpi_driver_data(device); + struct acpi_video_device *video = cooling_dev->devdata; unsigned long long level; int offset; @@ -283,8 +281,7 @@ static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, static int video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state) { - struct acpi_device *device = cooling_dev->devdata; - struct acpi_video_device *video = acpi_driver_data(device); + struct acpi_video_device *video = cooling_dev->devdata; int level; if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL) @@ -1125,7 +1122,6 @@ static int acpi_video_bus_get_one_device(struct acpi_device *device, void *arg) strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME); strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS); - device->driver_data = data; data->device_id = device_id; data->video = video; @@ -1747,8 +1743,8 @@ static void acpi_video_dev_register_backlight(struct acpi_video_device *device) device->backlight->props.brightness = acpi_video_get_brightness(device->backlight); - device->cooling_dev = thermal_cooling_device_register("LCD", - device->dev, &video_cooling_ops); + device->cooling_dev = thermal_cooling_device_register("LCD", device, + &video_cooling_ops); if (IS_ERR(device->cooling_dev)) { /* * Set cooling_dev to NULL so we don't crash trying to free it.