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 2E9C0C32771 for ; Tue, 27 Sep 2022 01:33:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229871AbiI0Bd5 (ORCPT ); Mon, 26 Sep 2022 21:33:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229559AbiI0Bd4 (ORCPT ); Mon, 26 Sep 2022 21:33:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF1E6F3912; Mon, 26 Sep 2022 18:33:55 -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 1DA2E6150C; Tue, 27 Sep 2022 01:33:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6047FC433C1; Tue, 27 Sep 2022 01:33:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664242433; bh=ZT3oXGhAudvES/gLqMW1J/eJqd1J+wW1rTEmmcqBNtY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=shbj8/ezkc9lgD1K0T0SMcluJ1100Nsggnb1Ywgc2dNsqXr8jZB8Cuc3YUjxxxsf3 zMS14OFt6PVkdEFt6K+d0Lt03/cj5bkXE5F+p34PBsssjOrFaYM8lEErDT2lNzlVct ctiyLPkvgD2NL1TsTuUBFOZ46xizx0OrYkC41y6ZlTJL9yXi9UfXm0OaVmUde121wm 9jRyw9fb87q3+y1fE+ZQyKGlvb9+wPPkQLEZQiEIExKtUsFvl6j2EMmhxy4nqaUGKy ojNMxLBPp9y43V+QNxdB+zPtKrWXMT/LaTaSVd8yS6kUu8E9bF/FL5vi+kBujEMoi7 DZ4ZVbeoGMpxQ== Date: Mon, 26 Sep 2022 20:33:47 -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] wifi: nl80211: Split memcpy() of struct nl80211_wowlan_tcp_data_token flexible array Message-ID: References: <20220927003903.1941873-1-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220927003903.1941873-1-keescook@chromium.org> Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org On Mon, Sep 26, 2022 at 05:39:03PM -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 > --- > net/wireless/nl80211.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c > index 2705e3ee8fc4..461897933e92 100644 > --- a/net/wireless/nl80211.c > +++ b/net/wireless/nl80211.c > @@ -13171,7 +13171,8 @@ 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); There is a spurious '+' here............................................^^^ -- Gustavo > } > > trig->tcp = cfg; > -- > 2.34.1 >