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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43E21C6FA82 for ; Tue, 27 Sep 2022 19:46:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231269AbiI0Tq4 (ORCPT ); Tue, 27 Sep 2022 15:46:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230214AbiI0Tqz (ORCPT ); Tue, 27 Sep 2022 15:46:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 253271B3490; Tue, 27 Sep 2022 12:46:54 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id B5E0D61B1F; Tue, 27 Sep 2022 19:46:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2AD93C433D6; Tue, 27 Sep 2022 19:46:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664308013; bh=e5aDBKk9NK4a1QWira1pG3Pp+doScKrC1ane/mpBN3I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vHR+DB5QsrizGiSsJZYLaH8Bt36twqWRizKrEcipq/mH5ylFlLP/JfyTbKjwRgEVU Hv/hDy+wB1mer94r2Upk8FVHgZod9IzQwFKVVbvFWRDi80hl48GhsKe9YIyQHJFTWA 9+zMDPiHZ6G34TfdaemGQvHV1Jfu1dtKWV/Af+wXQYhWUyzYEiZXy0SePk60zjZEcM JeHuJhLusgrvh7ZsixQzCv5BZdeOaywcpblMZcnMvkURpDrHKyItYu62lNMKtT2JRF ueWbQnxnevo2BcnALQQc6N7HKhvw80xBt7lhrxhqkJUZnF2bDWY3F34gomxsv3MEb9 TGoZw9qT08oSQ== Date: Tue, 27 Sep 2022 14:46:47 -0500 From: "Gustavo A. R. Silva" To: Kees Cook Cc: Johannes Berg , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH v2] wifi: nl80211: Split memcpy() of struct nl80211_wowlan_tcp_data_token flexible array Message-ID: References: <20220927022923.1956205-1-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220927022923.1956205-1-keescook@chromium.org> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Sep 26, 2022 at 07:29:23PM -0700, Kees Cook wrote: > To work around a misbehavior of the compiler's ability to see into > composite flexible array structs (as detailed in the coming memcpy() > hardening series[1]), split the memcpy() of the header and the payload > so no false positive run-time overflow warning will be generated. > > [1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@chromium.org/ > > Cc: Johannes Berg > Cc: "David S. Miller" > Cc: Eric Dumazet > Cc: Jakub Kicinski > Cc: Paolo Abeni > Cc: linux-wireless@vger.kernel.org > Cc: netdev@vger.kernel.org > Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva Thanks! -- Gustavo > --- > v2: - fix typo leading "+" (Gustavo) > v1: https://lore.kernel.org/lkml/20220927003903.1941873-1-keescook@chromium.org > --- > net/wireless/nl80211.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c > index 2705e3ee8fc4..169e3ec33466 100644 > --- a/net/wireless/nl80211.c > +++ b/net/wireless/nl80211.c > @@ -13171,7 +13171,9 @@ static int nl80211_parse_wowlan_tcp(struct cfg80211_registered_device *rdev, > wake_mask_size); > if (tok) { > cfg->tokens_size = tokens_size; > - memcpy(&cfg->payload_tok, tok, sizeof(*tok) + tokens_size); > + cfg->payload_tok = *tok; > + memcpy(cfg->payload_tok.token_stream, tok->token_stream, > + tokens_size); > } > > trig->tcp = cfg; > -- > 2.34.1 >