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 71F9FC07E9D for ; Mon, 26 Sep 2022 11:20:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237783AbiIZLUy (ORCPT ); Mon, 26 Sep 2022 07:20:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237812AbiIZLTD (ORCPT ); Mon, 26 Sep 2022 07:19:03 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDBFD52E56; Mon, 26 Sep 2022 03:38:38 -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 ams.source.kernel.org (Postfix) with ESMTPS id 6AA2BB80957; Mon, 26 Sep 2022 10:38:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD622C433C1; Mon, 26 Sep 2022 10:38:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1664188704; bh=STN83xp9evJqJZLuHCkw/lnhnKc/4/65pi4u/jxUtL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p4oudoJFzw3en4IWk/RrcGsRD4xBXHKw0f/DWz8LqTEsH/Sut+lL0fxbqMaCR3mtG QNrrC8PRvC35O/h1P88YYxioA9O1AWWdyOqCl/AtfKTyIwWCdthtejiz4wUwxsKoho KUe0nfcQMKS8q9m0qQaQnXtvZxSR2JC+GE4foImg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Jason A. Donenfeld" , Kees Cook , syzbot+a448cda4dba2dac50de5@syzkaller.appspotmail.com, Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 095/148] wireguard: netlink: avoid variable-sized memcpy on sockaddr Date: Mon, 26 Sep 2022 12:12:09 +0200 Message-Id: <20220926100759.641942551@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220926100756.074519146@linuxfoundation.org> References: <20220926100756.074519146@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason A. Donenfeld [ Upstream commit 26c013108c12b94bc023bf19198a4300596c98b1 ] Doing a variable-sized memcpy is slower, and the compiler isn't smart enough to turn this into a constant-size assignment. Further, Kees' latest fortified memcpy will actually bark, because the destination pointer is type sockaddr, not explicitly sockaddr_in or sockaddr_in6, so it thinks there's an overflow: memcpy: detected field-spanning write (size 28) of single field "&endpoint.addr" at drivers/net/wireguard/netlink.c:446 (size 16) Fix this by just assigning by using explicit casts for each checked case. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Reviewed-by: Kees Cook Reported-by: syzbot+a448cda4dba2dac50de5@syzkaller.appspotmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/wireguard/netlink.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c index d0f3b6d7f408..5c804bcabfe6 100644 --- a/drivers/net/wireguard/netlink.c +++ b/drivers/net/wireguard/netlink.c @@ -436,14 +436,13 @@ static int set_peer(struct wg_device *wg, struct nlattr **attrs) if (attrs[WGPEER_A_ENDPOINT]) { struct sockaddr *addr = nla_data(attrs[WGPEER_A_ENDPOINT]); size_t len = nla_len(attrs[WGPEER_A_ENDPOINT]); + struct endpoint endpoint = { { { 0 } } }; - if ((len == sizeof(struct sockaddr_in) && - addr->sa_family == AF_INET) || - (len == sizeof(struct sockaddr_in6) && - addr->sa_family == AF_INET6)) { - struct endpoint endpoint = { { { 0 } } }; - - memcpy(&endpoint.addr, addr, len); + if (len == sizeof(struct sockaddr_in) && addr->sa_family == AF_INET) { + endpoint.addr4 = *(struct sockaddr_in *)addr; + wg_socket_set_peer_endpoint(peer, &endpoint); + } else if (len == sizeof(struct sockaddr_in6) && addr->sa_family == AF_INET6) { + endpoint.addr6 = *(struct sockaddr_in6 *)addr; wg_socket_set_peer_endpoint(peer, &endpoint); } } -- 2.35.1