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 X-Spam-Level: X-Spam-Status: No, score=-12.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 3A413C433E1 for ; Fri, 21 Aug 2020 16:56:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0359B20702 for ; Fri, 21 Aug 2020 16:56:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="Na8jhfRp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728476AbgHUQz6 (ORCPT ); Fri, 21 Aug 2020 12:55:58 -0400 Received: from rnd-relay.smtp.broadcom.com ([192.19.229.170]:39806 "EHLO rnd-relay.smtp.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728644AbgHUQwj (ORCPT ); Fri, 21 Aug 2020 12:52:39 -0400 Received: from mail-irv-17.broadcom.com (mail-irv-17.lvn.broadcom.net [10.75.242.48]) by rnd-relay.smtp.broadcom.com (Postfix) with ESMTP id 3386A30C193; Fri, 21 Aug 2020 09:49:56 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.10.3 rnd-relay.smtp.broadcom.com 3386A30C193 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=broadcom.com; s=dkimrelay; t=1598028596; bh=1N277qLlwPe3wO79G1bB+4oXclXO8d32DbZS3HyRadQ=; h=From:To:Cc:Subject:Date:From; b=Na8jhfRpR8y7lbNjf/dOMgpbj+FQLlA1dRc4fIZ+D0+31C9SQvuEbj1prGbmHy/qx sTfb5MFF9KTPXm9U58ayVkcd0V4rkHJfkmgPOUJE8uZ/RbcngSR/H8FMG+XZODwRuW 7M9RXa5z4lFxHhdCsw1O2iAOXrcVFhOvWY52B85U= Received: from lbrmn-mmayer.ric.broadcom.net (lbrmn-mmayer.ric.broadcom.net [10.136.28.150]) by mail-irv-17.broadcom.com (Postfix) with ESMTP id E31A214008D; Fri, 21 Aug 2020 09:52:32 -0700 (PDT) From: Markus Mayer To: Florian Fainelli , Colin Ian King , Krzysztof Kozlowski Cc: Markus Mayer , BCM Kernel Feedback , Linux ARM Kernel , Linux Kernel Subject: [PATCH v2] memory: brcmstb_dpfe: fix array index out of bounds Date: Fri, 21 Aug 2020 09:52:21 -0700 Message-Id: <20200821165221.32267-1-mmayer@broadcom.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We would overrun the error_text array if we hit a TIMEOUT condition, because we were using the error code "ETIMEDOUT" (which is 110) as an array index. We fix the problem by correcting the array index and by providing a function to retrieve error messages rather than accessing the array directly. The function includes a bounds check that prevents the array from being overrun. This patch was prepared in response to https://lkml.org/lkml/2020/8/18/505. Signed-off-by: Markus Mayer Acked-by: Florian Fainelli --- Changes since v1: - Added link of the coverity report to the commit message. - Added Florian's ack. - Removed second "const" from get_error_text() return type (thanks to the kernel test robot). drivers/memory/brcmstb_dpfe.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/memory/brcmstb_dpfe.c b/drivers/memory/brcmstb_dpfe.c index e08528b12cbd..dcf50bb8dd69 100644 --- a/drivers/memory/brcmstb_dpfe.c +++ b/drivers/memory/brcmstb_dpfe.c @@ -188,11 +188,6 @@ struct brcmstb_dpfe_priv { struct mutex lock; }; -static const char * const error_text[] = { - "Success", "Header code incorrect", "Unknown command or argument", - "Incorrect checksum", "Malformed command", "Timed out", -}; - /* * Forward declaration of our sysfs attribute functions, so we can declare the * attribute data structures early. @@ -307,6 +302,20 @@ static const struct dpfe_api dpfe_api_v3 = { }, }; +static const char *get_error_text(unsigned int i) +{ + static const char * const error_text[] = { + "Success", "Header code incorrect", + "Unknown command or argument", "Incorrect checksum", + "Malformed command", "Timed out", "Unknown error", + }; + + if (unlikely(i >= ARRAY_SIZE(error_text))) + i = ARRAY_SIZE(error_text) - 1; + + return error_text[i]; +} + static bool is_dcpu_enabled(struct brcmstb_dpfe_priv *priv) { u32 val; @@ -445,7 +454,7 @@ static int __send_command(struct brcmstb_dpfe_priv *priv, unsigned int cmd, } if (resp != 0) { mutex_unlock(&priv->lock); - return -ETIMEDOUT; + return -ffs(DCPU_RET_ERR_TIMEDOUT); } /* Compute checksum over the message */ @@ -695,7 +704,7 @@ static ssize_t generic_show(unsigned int command, u32 response[], ret = __send_command(priv, command, response); if (ret < 0) - return sprintf(buf, "ERROR: %s\n", error_text[-ret]); + return sprintf(buf, "ERROR: %s\n", get_error_text(-ret)); return 0; } -- 2.17.1