From nobody Wed Sep 3 06:44:33 2025 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 D0851ECAAA1 for ; Mon, 24 Oct 2022 13:21:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235932AbiJXNVq (ORCPT ); Mon, 24 Oct 2022 09:21:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236439AbiJXNU2 (ORCPT ); Mon, 24 Oct 2022 09:20:28 -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 98B1B29CB0; Mon, 24 Oct 2022 05:29:01 -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 B73EFB8119E; Mon, 24 Oct 2022 12:04:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16FC9C433D6; Mon, 24 Oct 2022 12:04:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666613090; bh=/K/z/rK+8z3Z74OMUw1WBkuyfmRSNZoUhy4sU47g0Yk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X+aJkKuPnV3DOjrJbOY+ndxIzR5G5RTqAuyUaTASLNm27IrtXPlpruNzqiBEq03Qx XEk7WWM2MYuza49VqnrbM8Cf5MdUDcHoyKvKw7yz8Rqya/Taoz+QI8iRTBbGXZ/HVV UDI6SeOyj5AYlvYxF4W37f1+0qTZSi371gGZ0npw= 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 4.19 223/229] net/ieee802154: dont warn zero-sized raw_sendmsg() Date: Mon, 24 Oct 2022 13:32:22 +0200 Message-Id: <20221024113006.476744345@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024112959.085534368@linuxfoundation.org> References: <20221024112959.085534368@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 =3D=3D 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 =3D { .sin_family =3D AF_INET, .sin_addr.s_addr= =3D htonl(INADDR_LOOPBACK) }; struct iovec iov =3D { }; struct msghdr hdr =3D { .msg_name =3D &addr, .msg_namelen =3D sizeof(ad= dr), .msg_iov =3D &iov, .msg_iovlen =3D 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 =3D=3D 0 was acceptable for at least PF_IEEE802154 socket. Link: https://syzkaller.appspot.com/bug?extid=3D5ea725c25d06fb9114c4 [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(+) --- a/net/ieee802154/socket.c +++ b/net/ieee802154/socket.c @@ -285,6 +285,10 @@ static int raw_sendmsg(struct sock *sk, err =3D -EMSGSIZE; goto out_dev; } + if (!size) { + err =3D 0; + goto out_dev; + } =20 hlen =3D LL_RESERVED_SPACE(dev); tlen =3D dev->needed_tailroom;