From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D304C433F5 for ; Wed, 16 Feb 2022 12:22:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233120AbiBPMW5 (ORCPT ); Wed, 16 Feb 2022 07:22:57 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:45274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232537AbiBPMWx (ORCPT ); Wed, 16 Feb 2022 07:22:53 -0500 Received: from mail-yb1-f179.google.com (mail-yb1-f179.google.com [209.85.219.179]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5CE3E0ACD; Wed, 16 Feb 2022 04:22:41 -0800 (PST) Received: by mail-yb1-f179.google.com with SMTP id y6so5472316ybc.5; Wed, 16 Feb 2022 04:22:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=iyLKMy9mx/11boOTHLHDZ1fvODjQEjXMH8nu+p70vJs=; b=fu7P9kBBg/MMvjWN/lY+KqPqg5ZeeTgIhKde0G5jS4IReQm1ayXYZDJIXQDu7eYx5W UDzC6byGHhB+AD3r9ZJoqVe7O6CbkRwqAKncma2EVVgZxlVs14zHjsxraT6+UUcYggFF JFonXefseGKRWL5X9FAaucy6a85Z4N9QkvGI1uVpC3TNWBYtCQBNK+xOEPbGEPjQow2c kRw1wTu+1pukSE9JYFmy5EVxrRAzZueZmXnoJwNFkkBl3XIliQ2l/VSj6aVCTKuMKjNQ PA7i2rlCMN5ZEihsll8X604d+1/3bCi/jrHcEh4OkM51ZfX2qJ3mFhVB+lHP5Tn42IMx tCmw== X-Gm-Message-State: AOAM532OsAeIAILBZEos0gr54EgTTkJYNXDN7/ujBaq2yATtJ4qbEI72 B10MyvVHdZS5eNSJPtuxLXi1AZYnRJYk/13Z+xg= X-Google-Smtp-Source: ABdhPJyJxNNVakBSB/WLvTRdrGZ9BXqx/DQIqoqFOGeLTAEwWDJchTaLwydj6Vd4o58xgwmHfILAH+X1f5I0myuczl4= X-Received: by 2002:a0d:d5d6:0:b0:2d1:51e2:5a09 with SMTP id x205-20020a0dd5d6000000b002d151e25a09mr2027246ywd.149.1645014161118; Wed, 16 Feb 2022 04:22:41 -0800 (PST) MIME-Version: 1.0 References: <20220216062615.779778-1-ztong0001@gmail.com> In-Reply-To: <20220216062615.779778-1-ztong0001@gmail.com> From: "Rafael J. Wysocki" Date: Wed, 16 Feb 2022 13:22:27 +0100 Message-ID: Subject: Re: [PATCH] ACPICA: proactively check null ptr to avoid API misuse To: Tong Zhang Cc: Robert Moore , "Rafael J. Wysocki" , Len Brown , ACPI Devel Maling List , "open list:ACPI COMPONENT ARCHITECTURE (ACPICA)" , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 16, 2022 at 7:26 AM Tong Zhang wrote: > > There are some cases that user use acpi_ns_walk_namespace() without > checking acpi_disable flag. When acpi=off is provided in boot cmdline, > acpi_gbl_root_node is NULL and calling acpi_ns_walk_namespace() will > crash kernel. In order to avoid such misuse, we proactively check null ptr > and return an error when we know ACPI is disabled. The issue should be fixed by this commit in the upstream ACPICA code base: https://github.com/acpica/acpica/commit/b1c3656ef4950098e530be68d4b589584f06cddc > > Signed-off-by: Tong Zhang > --- > drivers/acpi/acpica/nswalk.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/acpi/acpica/nswalk.c b/drivers/acpi/acpica/nswalk.c > index 915c2433463d..9ae45db16d86 100644 > --- a/drivers/acpi/acpica/nswalk.c > +++ b/drivers/acpi/acpica/nswalk.c > @@ -171,6 +171,13 @@ acpi_ns_walk_namespace(acpi_object_type type, > start_node = acpi_gbl_root_node; > } > > + /* acpi_gbl_root_node is NULL when acpi=off is provided. > + * We proactively check nulliness here and return an error if user call > + * this function without checking acpi_disabled > + */ > + if (start_node == NULL) > + return_ACPI_STATUS(AE_ERROR); > + > /* Null child means "get first node" */ > > parent_node = start_node; > -- > 2.25.1 >