From patchwork Sat Feb 20 12:24:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 385424 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12E5AC43332 for ; Sat, 20 Feb 2021 12:26:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA88664EDB for ; Sat, 20 Feb 2021 12:26:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229678AbhBTM0V (ORCPT ); Sat, 20 Feb 2021 07:26:21 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:47484 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229657AbhBTM0Q (ORCPT ); Sat, 20 Feb 2021 07:26:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1613823890; 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=xABmbysZEbKQ7tqZDCIsmVUSOCJTc6/N9SEah+SR7no=; b=fyERRjDZ3wNmPFJNxnzhQu4HTmTVRIS8K7Eyya90embJsz06liIOssUsmnRC4aE0yUPK33 pfzLJTlOdy65ALNUbdhMAO/AHUjxtjrI4VTdMkhAL2l87H8AMrxMLyDQqs1+JiAhFRIxoX p5bGoIsYIDUYH4dFm1lkk+W7I53IoSc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-446-qwCdnOxIPqa2_lxHZ3tv5Q-1; Sat, 20 Feb 2021 07:24:48 -0500 X-MC-Unique: qwCdnOxIPqa2_lxHZ3tv5Q-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A880B1009619; Sat, 20 Feb 2021 12:24:47 +0000 (UTC) Received: from x1.localdomain.com (ovpn-112-29.ams2.redhat.com [10.36.112.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8585410016FF; Sat, 20 Feb 2021 12:24:46 +0000 (UTC) From: Hans de Goede To: Jiri Kosina , Benjamin Tissoires Cc: Hans de Goede , linux-input@vger.kernel.org, linux-leds@vger.kernel.org Subject: [PATCH v2 3/7] HID: lenovo: Check hid_get_drvdata() returns non NULL in lenovo_event() Date: Sat, 20 Feb 2021 13:24:34 +0100 Message-Id: <20210220122438.21857-4-hdegoede@redhat.com> In-Reply-To: <20210220122438.21857-1-hdegoede@redhat.com> References: <20210220122438.21857-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org The HID lenovo probe function only attaches drvdata to one of the USB interfaces, but lenovo_event() will get called for all USB interfaces to which hid-lenovo is bound. This allows a malicious device to fake being a device handled by hid-lenovo, which generates events for which lenovo_event() has special handling (and thus dereferences hid_get_drvdata()) on another interface triggering a NULL pointer exception. Add a check for hid_get_drvdata() returning NULL, avoiding this possible NULL pointer exception. Fixes: bc04b37ea0ec ("HID: lenovo: Add ThinkPad 10 Ultrabook Keyboard support") Signed-off-by: Hans de Goede Reviewed-by: Marek Behún --- drivers/hid/hid-lenovo.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c index 49b8767a8d30..f1868b5d9b58 100644 --- a/drivers/hid/hid-lenovo.c +++ b/drivers/hid/hid-lenovo.c @@ -502,6 +502,9 @@ static int lenovo_event_cptkbd(struct hid_device *hdev, static int lenovo_event(struct hid_device *hdev, struct hid_field *field, struct hid_usage *usage, __s32 value) { + if (!hid_get_drvdata(hdev)) + return 0; + switch (hdev->product) { case USB_DEVICE_ID_LENOVO_CUSBKBD: case USB_DEVICE_ID_LENOVO_CBTKBD: