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 E84CEFA3740 for ; Mon, 24 Oct 2022 13:00:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234873AbiJXNAb (ORCPT ); Mon, 24 Oct 2022 09:00:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234979AbiJXM7E (ORCPT ); Mon, 24 Oct 2022 08:59:04 -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 72E709938C; Mon, 24 Oct 2022 05:17:53 -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 54423612A0; Mon, 24 Oct 2022 12:15:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67CF2C433D6; Mon, 24 Oct 2022 12:15:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666613739; bh=QR3O8uBGc8eFe5nbi7RUEstzEsOIsXyPelHp6Zn1iTs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dxVH7Ne8WvT78ALfv5lTlAiK85dySVsHB8C9t9NqG2l8w5yPk27UJzEOWVM6TtWte Zb+yibEJGcJTpou4ltEs1++AIdy/f6FG2TBNZj0V2EcDPOKX+4p40/aJbZK0j+1tfW xBQEs/MUNlFbbqYjYqwfPKcKcCLwUbWJKbpsaUYA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Tetsuo Handa , Alexander Aring , Stefan Schmidt , Sasha Levin Subject: [PATCH 5.4 250/255] net/ieee802154: dont warn zero-sized raw_sendmsg() Date: Mon, 24 Oct 2022 13:32:40 +0200 Message-Id: <20221024113011.611161417@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024113002.471093005@linuxfoundation.org> References: <20221024113002.471093005@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: stable@vger.kernel.org From: Tetsuo Handa [ Upstream commit b12e924a2f5b960373459c8f8a514f887adf5cac ] syzbot is hitting skb_assert_len() warning at __dev_queue_xmit() [1], for PF_IEEE802154 socket's zero-sized raw_sendmsg() request is hitting __dev_queue_xmit() with skb->len == 0. Since PF_IEEE802154 socket's zero-sized raw_sendmsg() request was able to return 0, don't call __dev_queue_xmit() if packet length is 0. ---------- #include #include int main(int argc, char *argv[]) { struct sockaddr_in addr = { .sin_family = AF_INET, .sin_addr.s_addr = htonl(INADDR_LOOPBACK) }; struct iovec iov = { }; struct msghdr hdr = { .msg_name = &addr, .msg_namelen = sizeof(addr), .msg_iov = &iov, .msg_iovlen = 1 }; sendmsg(socket(PF_IEEE802154, SOCK_RAW, 0), &hdr, 0); return 0; } ---------- Note that this might be a sign that commit fd1894224407c484 ("bpf: Don't redirect packets with invalid pkt_len") should be reverted, for skb->len == 0 was acceptable for at least PF_IEEE802154 socket. Link: https://syzkaller.appspot.com/bug?extid=5ea725c25d06fb9114c4 [1] Reported-by: syzbot Fixes: fd1894224407c484 ("bpf: Don't redirect packets with invalid pkt_len") Signed-off-by: Tetsuo Handa Signed-off-by: Alexander Aring Link: https://lore.kernel.org/r/20221005014750.3685555-2-aahringo@redhat.com Signed-off-by: Stefan Schmidt Signed-off-by: Sasha Levin --- net/ieee802154/socket.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ieee802154/socket.c b/net/ieee802154/socket.c index a92b11999e5f..6d6c28581770 100644 --- a/net/ieee802154/socket.c +++ b/net/ieee802154/socket.c @@ -273,6 +273,10 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) err = -EMSGSIZE; goto out_dev; } + if (!size) { + err = 0; + goto out_dev; + } hlen = LL_RESERVED_SPACE(dev); tlen = dev->needed_tailroom; -- 2.35.1