From patchwork Tue Mar 7 23:01:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacob Keller X-Patchwork-Id: 13164923 X-Patchwork-Delegate: kvalo@adurom.com 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 44ACCC678D5 for ; Tue, 7 Mar 2023 23:03:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230155AbjCGXDX (ORCPT ); Tue, 7 Mar 2023 18:03:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230078AbjCGXDB (ORCPT ); Tue, 7 Mar 2023 18:03:01 -0500 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1BF21C589 for ; Tue, 7 Mar 2023 15:01:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1678230117; x=1709766117; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=NMFFgd/dfwYtUJPj6wj76EkQ/s/ZrzsbXJSv1hnrUMA=; b=G85cb9p9HDArDLevNZdYIKHZdLbrobFpr6Cyq7GI7CzEExLOwq14gUyt A1nkdV5oCBE+cPbXxd6LtP7SL5oSbrS3YS/DP12UgmPfw6OIlg7NDNyAa QQ7jhnI8z/hS0h74evxvnyyLXbuoL6KEWMNOC7DgIC4r0yRMI/U57a46u CH6zFcE7Dut18GabaTg6+VnHeCHOipkj766GgNvSX6nNfAVgLbe2HOCTn xkNBqZ5i8V6A9//Cu5CyNjig6oQaCwPBQp3o+Vui3mll3Cf6gHUDYJonH 810ZyPB7eYJWXSlw2Z7KKbL3AQ5N9F8WmcNodH+19Pc1dTEk7kr93DILc g==; X-IronPort-AV: E=McAfee;i="6500,9779,10642"; a="363632839" X-IronPort-AV: E=Sophos;i="5.98,242,1673942400"; d="scan'208";a="363632839" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Mar 2023 15:01:57 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10642"; a="679121129" X-IronPort-AV: E=Sophos;i="5.98,242,1673942400"; d="scan'208";a="679121129" Received: from jekeller-desk.amr.corp.intel.com (HELO jekeller-desk.jekeller.internal) ([10.166.241.1]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Mar 2023 15:01:56 -0800 From: Jacob Keller To: Kalle Valo Cc: Johannes Berg , linux-wireless@vger.kernel.org, Jacob Keller , Stanislav Yakovlev Subject: [PATCH v2] wifi: ipw2x00: convert ipw_fw_error->elem to flexible array[] Date: Tue, 7 Mar 2023 15:01:48 -0800 Message-Id: <20230307230148.3735684-1-jacob.e.keller@intel.com> X-Mailer: git-send-email 2.39.1.405.gd4c25cc71f83 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org The ipw_fw_error structure contains a payload[] flexible array as well as two pointers to this array area, ->elem, and ->log. The total size of the allocated structure is computed without use of the macros. There's no reason to keep both a payload[] and an extra pointer to both the elem and log members. Convert the elem pointer member into the flexible array member, removing payload. Fix the allocation of the ipw_fw_error structure to use size_add(), struct_size(), and array_size() to compute the allocation. This ensures that any overflow saturates at SIZE_MAX rather than overflowing and potentially allowing an undersized allocation. Before the structure change, the layout of ipw_fw_error was: struct ipw_fw_error { long unsigned int jiffies; /* 0 8 */ u32 status; /* 8 4 */ u32 config; /* 12 4 */ u32 elem_len; /* 16 4 */ u32 log_len; /* 20 4 */ struct ipw_error_elem * elem; /* 24 8 */ struct ipw_event * log; /* 32 8 */ u8 payload[]; /* 40 0 */ /* size: 40, cachelines: 1, members: 8 */ /* last cacheline: 40 bytes */ }; After this change, the layout is now: struct ipw_fw_error { long unsigned int jiffies; /* 0 8 */ u32 status; /* 8 4 */ u32 config; /* 12 4 */ u32 elem_len; /* 16 4 */ u32 log_len; /* 20 4 */ struct ipw_event * log; /* 24 8 */ struct ipw_error_elem elem[]; /* 32 0 */ /* size: 32, cachelines: 1, members: 7 */ /* last cacheline: 32 bytes */ }; This saves a total of 8 bytes for every ipw_fw_error allocation, and removes the risk of a potential overflow on the allocation. Signed-off-by: Jacob Keller Cc: Stanislav Yakovlev --- This was discovered by a coccinelle patch I developed, and submitted at: https://lore.kernel.org/all/20230227202428.3657443-1-jacob.e.keller@intel.com/ V1: https://lore.kernel.org/linux-wireless/99a9d4a2-d032-1c9d-90c6-3a68f6b3a092@intel.com/ Changes since v1 * Split series into individual postings to avoid confusion about dependency drivers/net/wireless/intel/ipw2x00/ipw2200.c | 7 +++---- drivers/net/wireless/intel/ipw2x00/ipw2200.h | 3 +-- 2 files changed, 4 insertions(+), 6 deletions(-) base-commit: 8f9850dd8d23c1290cb642ce9548a440da5771ec diff --git a/drivers/net/wireless/intel/ipw2x00/ipw2200.c b/drivers/net/wireless/intel/ipw2x00/ipw2200.c index d382f2017325..b91b1a2d0be7 100644 --- a/drivers/net/wireless/intel/ipw2x00/ipw2200.c +++ b/drivers/net/wireless/intel/ipw2x00/ipw2200.c @@ -1234,9 +1234,9 @@ static struct ipw_fw_error *ipw_alloc_error_log(struct ipw_priv *priv) u32 base = ipw_read32(priv, IPW_ERROR_LOG); u32 elem_len = ipw_read_reg32(priv, base); - error = kmalloc(sizeof(*error) + - sizeof(*error->elem) * elem_len + - sizeof(*error->log) * log_len, GFP_ATOMIC); + error = kmalloc(size_add(struct_size(error, elem, elem_len), + array_size(sizeof(*error->log), log_len)), + GFP_ATOMIC); if (!error) { IPW_ERROR("Memory allocation for firmware error log " "failed.\n"); @@ -1247,7 +1247,6 @@ static struct ipw_fw_error *ipw_alloc_error_log(struct ipw_priv *priv) error->config = priv->config; error->elem_len = elem_len; error->log_len = log_len; - error->elem = (struct ipw_error_elem *)error->payload; error->log = (struct ipw_event *)(error->elem + elem_len); ipw_capture_event_log(priv, log_len, error->log); diff --git a/drivers/net/wireless/intel/ipw2x00/ipw2200.h b/drivers/net/wireless/intel/ipw2x00/ipw2200.h index 09ddd21608d4..8ebf09121e17 100644 --- a/drivers/net/wireless/intel/ipw2x00/ipw2200.h +++ b/drivers/net/wireless/intel/ipw2x00/ipw2200.h @@ -1106,9 +1106,8 @@ struct ipw_fw_error { /* XXX */ u32 config; u32 elem_len; u32 log_len; - struct ipw_error_elem *elem; struct ipw_event *log; - u8 payload[]; + struct ipw_error_elem elem[]; } __packed; #ifdef CONFIG_IPW2200_PROMISCUOUS