From patchwork Wed Feb 16 06:26:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tong Zhang X-Patchwork-Id: 543416 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 04A5DC433F5 for ; Wed, 16 Feb 2022 06:26:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229619AbiBPG0l (ORCPT ); Wed, 16 Feb 2022 01:26:41 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:50072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229497AbiBPG0l (ORCPT ); Wed, 16 Feb 2022 01:26:41 -0500 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 658881DA0D9; Tue, 15 Feb 2022 22:26:20 -0800 (PST) Received: by mail-pj1-x1029.google.com with SMTP id y9so1584858pjf.1; Tue, 15 Feb 2022 22:26:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=dBNXgCdgCYaUbBErPqT71h5+5QqoItuAWvehu3xJcaw=; b=LSeae50hst2QZlr14S+ETUone/JD5gLfA68GnptsxgIutLesAhfCxK81SVXKYTWy9e I1Knah+bE7toxoWwtlRValeGLk4fV0CfxlFMIcRM9wMriZn0l8ugQVFLTJxaHr/rwKKi lFF4W+igSt0HJXM6fQKQSSecTWRJU5ftmBj4XDzTReXJINYUQxIjMjWvgct6QlpHi19q PXDJelr6TPMJaFsxKcTvBuh0PQ0Z63nXhdb2KVRUeo40zupZ2dejLRdPxglWUdBWsNws 2nA5uWGrP8wFcMpSAH8p/KVH1sk/KJsmI+KkXRzb8bUiD1Tj6eXNFeK7hi+PROuwDb9l frFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=dBNXgCdgCYaUbBErPqT71h5+5QqoItuAWvehu3xJcaw=; b=00q5IqqkYWvIWL9J7Vq9PPLY6/NEkrQ6pGYxhHQ8zPJZ2UbjfRSxTlPJBd+2xLx5/G yS4ECyEV0JZHz3g3tk9b0cwrXadikIVDPmbFTW9N5sEk2Ly9CNyPKC22W7OWBPHIvXDc wMW6M5EC5n01u04YUvSQ743eSPDV3RQsaYx1rBeLqtycYsD+itMNyBd0ORxXOW2Hpg/9 2zhKzjfxsPxbNaW9bHDu09xHjZJz3XtdcIksTBrnL/j7FneI1/hb2aazoIwDPgjA8z9m +wVT//5ZRxsQMhRMIc1TwmNEhhyqAZvkFo2lA/q2zM+Famw/cN21PPgxA8trt2qiXunM KXNQ== X-Gm-Message-State: AOAM532kBBdNhPjzLQmL7Mye72qwWB0CAllTKJW6pxd+d3fZNKfldfos 8jsSyksLAh8JJpN5hSyCEMw= X-Google-Smtp-Source: ABdhPJzvIyQ1ZKKBf53vZodnhgWF6ft6bdVdQOoopcsO/RIGfL50H98k8yCPMcS1jDNq0Q22m1+QUQ== X-Received: by 2002:a17:90a:d987:b0:1b8:f46d:1b83 with SMTP id d7-20020a17090ad98700b001b8f46d1b83mr69279pjv.221.1644992779671; Tue, 15 Feb 2022 22:26:19 -0800 (PST) Received: from ubuntu-server.local ([2600:1700:3ec7:421f:fd1e:ea7b:d4f8:959b]) by smtp.googlemail.com with ESMTPSA id q16sm43487079pfu.194.2022.02.15.22.26.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Feb 2022 22:26:19 -0800 (PST) From: Tong Zhang To: Robert Moore , "Rafael J. Wysocki" , Len Brown , linux-acpi@vger.kernel.org, devel@acpica.org, linux-kernel@vger.kernel.org Cc: Tong Zhang Subject: [PATCH] ACPICA: proactively check null ptr to avoid API misuse Date: Tue, 15 Feb 2022 22:26:15 -0800 Message-Id: <20220216062615.779778-1-ztong0001@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org 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. 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;