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 9ED90C4167B for ; Mon, 24 Jan 2022 20:11:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379377AbiAXULU (ORCPT ); Mon, 24 Jan 2022 15:11:20 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:49536 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378242AbiAXUGk (ORCPT ); Mon, 24 Jan 2022 15:06:40 -0500 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 45D59B8122F; Mon, 24 Jan 2022 20:06:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AEA4C340E5; Mon, 24 Jan 2022 20:06:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643054798; bh=U2lQl/MZ0d0+YaTq1QYVKR854nG4+BKuzrVJGOnA0c4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RmT19GfgKaPgmPtCOFkOKaFMAHxxmPBEcguIMka1TY2W89ONlxjMNAfKUYKoZRMUe mUN50MOdSTzMyexuQPGXY9Foprc0XO9msEz2a/ZS/xhfL1N8ANTkupCtIrMWs2/FHP FvD1o0QeAahHUfHGChi8el6LuWl8vnl6z5+g2Wng= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+983941aa85af6ded1fd9@syzkaller.appspotmail.com, Andrii Nakryiko , =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Alexei Starovoitov Subject: [PATCH 5.10 507/563] xdp: check prog type before updating BPF link Date: Mon, 24 Jan 2022 19:44:32 +0100 Message-Id: <20220124184042.004368957@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184024.407936072@linuxfoundation.org> References: <20220124184024.407936072@linuxfoundation.org> User-Agent: quilt/0.66 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: Toke Høiland-Jørgensen commit 382778edc8262b7535f00523e9eb22edba1b9816 upstream. The bpf_xdp_link_update() function didn't check the program type before updating the program, which made it possible to install any program type as an XDP program, which is obviously not good. Syzbot managed to trigger this by swapping in an LWT program on the XDP hook which would crash in a helper call. Fix this by adding a check and bailing out if the types don't match. Fixes: 026a4c28e1db ("bpf, xdp: Implement LINK_UPDATE for BPF XDP link") Reported-by: syzbot+983941aa85af6ded1fd9@syzkaller.appspotmail.com Acked-by: Andrii Nakryiko Signed-off-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/20220107221115.326171-1-toke@redhat.com Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -9339,6 +9339,12 @@ static int bpf_xdp_link_update(struct bp goto out_unlock; } old_prog = link->prog; + if (old_prog->type != new_prog->type || + old_prog->expected_attach_type != new_prog->expected_attach_type) { + err = -EINVAL; + goto out_unlock; + } + if (old_prog == new_prog) { /* no-op, don't disturb drivers */ bpf_prog_put(new_prog);