From patchwork Wed Feb 23 02:39:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 545877 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 01777C433FE for ; Wed, 23 Feb 2022 02:33:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237229AbiBWCeR (ORCPT ); Tue, 22 Feb 2022 21:34:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237581AbiBWCdP (ORCPT ); Tue, 22 Feb 2022 21:33:15 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04DC755499; Tue, 22 Feb 2022 18:31:19 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 962E6B81DD2; Wed, 23 Feb 2022 02:31:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E28BC340EB; Wed, 23 Feb 2022 02:31:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645583477; bh=b4fg9t+rSbYEnlrrD0PfvXHUsfVJWu2Xtp897/eWJBg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Jxmoj2CZYxA+OVt0dxFgPwPk1xHQXLNTX+kgiSqd95ArDpUICHRWVm39778T7thmd 7uBee3ECpqEZCNygF9cTUtPeNClyqd/5g3XjwUj+hxtst0lHzGRFAj+oyvuoATK7mz CLp2u3oGAvgHt6I+iFARqczW7Ha8ua9XJM9OsvuLoyLJ+O/xwxvzuB7/tn8kFtec4p e3svrFHfaZN+saF6QDWoVreAV6AkKuk6cNVIoqRxI+zWh0ES8HmvRkPNF1Skrhxdmt FUa1iuRrNynkXh06YzaysM9pzIKTayZC4NPh9pnvh0vLSgJls7/CqsY+Aog/JEVSJy TnvslMv0dp47Q== Date: Tue, 22 Feb 2022 20:39:11 -0600 From: "Gustavo A. R. Silva" To: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Kalle Valo , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-hardening@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH 6/6][next] ath6kl: wmi: Replace one-element array with flexible-array member in struct wmi_aplist_event Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Replace one-element array with flexible-array member in struct wmi_aplist_event. It's also worth noting that due to the flexible array transformation, the size of struct wmi_aplist_event changed (now the size is 8-byte smaller), and in order to preserve the logic of before the transformation, the following change is needed: - if (len < sizeof(struct wmi_aplist_event)) + if (len <= sizeof(struct wmi_aplist_event)) sizeof(struct wmi_aplist_event) before the flex-array transformation: struct wmi_aplist_event { u8 ap_list_ver; /* 0 1 */ u8 num_ap; /* 1 1 */ union wmi_ap_info ap_list[1]; /* 2 8 */ /* size: 10, cachelines: 1, members: 3 */ /* last cacheline: 10 bytes */ }; sizeof(struct wmi_aplist_event) after the flex-array transformation: struct wmi_aplist_event { u8 ap_list_ver; /* 0 1 */ u8 num_ap; /* 1 1 */ union wmi_ap_info ap_list[]; /* 2 0 */ /* size: 2, cachelines: 1, members: 3 */ /* last cacheline: 2 bytes */ }; Also, make use of the struct_size() helper and remove unneeded variable ap_info_entry_size. This issue was found with the help of Coccinelle and audited and fixed, manually. Link: https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Signed-off-by: Gustavo A. R. Silva --- Hi! It'd be great if someone can confirm or comment on the following changes described in the changelog text: - if (len < sizeof(struct wmi_aplist_event)) + if (len <= sizeof(struct wmi_aplist_event)) Thanks drivers/net/wireless/ath/ath6kl/wmi.c | 7 ++----- drivers/net/wireless/ath/ath6kl/wmi.h | 2 +- 2 files changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c index 645fb6cae3be..484d37e66ce6 100644 --- a/drivers/net/wireless/ath/ath6kl/wmi.c +++ b/drivers/net/wireless/ath/ath6kl/wmi.c @@ -1750,23 +1750,20 @@ static int ath6kl_wmi_snr_threshold_event_rx(struct wmi *wmi, u8 *datap, static int ath6kl_wmi_aplist_event_rx(struct wmi *wmi, u8 *datap, int len) { - u16 ap_info_entry_size; struct wmi_aplist_event *ev = (struct wmi_aplist_event *) datap; struct wmi_ap_info_v1 *ap_info_v1; u8 index; - if (len < sizeof(struct wmi_aplist_event) || + if (len <= sizeof(struct wmi_aplist_event) || ev->ap_list_ver != APLIST_VER1) return -EINVAL; - ap_info_entry_size = sizeof(struct wmi_ap_info_v1); ap_info_v1 = (struct wmi_ap_info_v1 *) ev->ap_list; ath6kl_dbg(ATH6KL_DBG_WMI, "number of APs in aplist event: %d\n", ev->num_ap); - if (len < (int) (sizeof(struct wmi_aplist_event) + - (ev->num_ap - 1) * ap_info_entry_size)) + if (len < struct_size(ev, ap_list, ev->num_ap)) return -EINVAL; /* AP list version 1 contents */ diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h b/drivers/net/wireless/ath/ath6kl/wmi.h index 6a7fc07cd9aa..a9732660192a 100644 --- a/drivers/net/wireless/ath/ath6kl/wmi.h +++ b/drivers/net/wireless/ath/ath6kl/wmi.h @@ -1957,7 +1957,7 @@ union wmi_ap_info { struct wmi_aplist_event { u8 ap_list_ver; u8 num_ap; - union wmi_ap_info ap_list[1]; + union wmi_ap_info ap_list[]; } __packed; /* Developer Commands */