From patchwork Fri Jun 10 08:17:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 580868 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 AA261C433EF for ; Fri, 10 Jun 2022 08:18:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347345AbiFJISp (ORCPT ); Fri, 10 Jun 2022 04:18:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347323AbiFJISU (ORCPT ); Fri, 10 Jun 2022 04:18:20 -0400 Received: from mail.baikalelectronics.com (mail.baikalelectronics.com [87.245.175.230]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0E183237943; Fri, 10 Jun 2022 01:18:17 -0700 (PDT) Received: from mail (mail.baikal.int [192.168.51.25]) by mail.baikalelectronics.com (Postfix) with ESMTP id B107E16A9; Fri, 10 Jun 2022 11:19:01 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.baikalelectronics.com B107E16A9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baikalelectronics.ru; s=mail; t=1654849141; bh=PZFSfsCT24HFXj3Ecc6Vn3a7tOVoW/wc6B5ZrH2r9og=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=AXhY9zFTvv4QQ7iOL8URRmLIIM/pOy7Hy827CSLgvOR1CjDCP+C6c+7daoF9YoA1q 2ui/tyTewWgnu27O0hNG3yj9obKCSnCeWEs7t5ywvlxKPmNEF5xDrtC14qOfcnsGxy Omone8uQoTehfJfcLYqq8WFgFVhcPkAq/8/R2NQ8= Received: from localhost (192.168.53.207) by mail (192.168.51.25) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Fri, 10 Jun 2022 11:18:09 +0300 From: Serge Semin To: Damien Le Moal , Hans de Goede , Jens Axboe , Hannes Reinecke CC: Serge Semin , Serge Semin , Alexey Malahov , Pavel Parkhomenko , Rob Herring , , , Subject: [PATCH v4 08/23] ata: libahci_platform: Sanity check the DT child nodes number Date: Fri, 10 Jun 2022 11:17:46 +0300 Message-ID: <20220610081801.11854-9-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20220610081801.11854-1-Sergey.Semin@baikalelectronics.ru> References: <20220610081801.11854-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Having greater than AHCI_MAX_PORTS (32) ports detected isn't that critical from the further AHCI-platform initialization point of view since exceeding the ports upper limit will cause allocating more resources than will be used afterwards. But detecting too many child DT-nodes doesn't seem right since it's very unlikely to have it on an ordinary platform. In accordance with the AHCI specification there can't be more than 32 ports implemented at least due to having the CAP.NP field of 5 bits wide and the PI register of dword size. Thus if such situation is found the DTB must have been corrupted and the data read from it shouldn't be reliable. Let's consider that as an erroneous situation and halt further resources allocation. Note it's logically more correct to have the nports set only after the initialization value is checked for being sane. So while at it let's make sure nports is assigned with a correct value. Signed-off-by: Serge Semin Reviewed-by: Hannes Reinecke --- Changelog v2: - Drop the else word from the child_nodes value checking if-else-if statement (@Damien) and convert the after-else part into the ternary operator-based statement. Changelog v4: - Fix some logical mistakes in the patch log. (@Sergei Shtylyov) --- drivers/ata/libahci_platform.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c index 814804582d1d..8aed7b29c7ab 100644 --- a/drivers/ata/libahci_platform.c +++ b/drivers/ata/libahci_platform.c @@ -451,15 +451,22 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev, } } - hpriv->nports = child_nodes = of_get_child_count(dev->of_node); + /* + * Too many sub-nodes most likely means having something wrong with + * the firmware. + */ + child_nodes = of_get_child_count(dev->of_node); + if (child_nodes > AHCI_MAX_PORTS) { + rc = -EINVAL; + goto err_out; + } /* * If no sub-node was found, we still need to set nports to * one in order to be able to use the * ahci_platform_[en|dis]able_[phys|regulators] functions. */ - if (!child_nodes) - hpriv->nports = 1; + hpriv->nports = child_nodes ?: 1; hpriv->phys = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->phys), GFP_KERNEL); if (!hpriv->phys) {