From nobody Thu Apr 2 10:43:03 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=quarantine dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1774861887; cv=none; d=zohomail.com; s=zohoarc; b=KT128AVuMwuE/2lNVGIgmCZjSOhtkfLkfECW4q1NdL/dFrkgWhl4MAEAaKpcomN3Pqzjja1ZFBkl7uPat0jhrFXpSs0YDxQbu0rI6jxBWIrNrfh+PIgsURUh73cpPsHyIQWTKhbE4SWJVkN8FCf2jsMCTwHwY9bNRPuoA1qhbBY= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1774861887; h=Content-Transfer-Encoding:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To:Cc; bh=UIjxUX2mjHNiOeF8MWR0J6MRSnLuzQeAzy0f09dGBzM=; b=DVwwMS6dj8D97d57maSoBmGGNrjM89VBoLNqZ0W0XagNaCwjiI6T9LzwJyCUcc5G+5IsyZ8mRT1JqYt344jNmQaLSs+mJrrI5GNJ7XjhMXytOE9oTZ+aIss0YEvmSDN6kuj/5XGp/tiG0CMbYwksLTRGzr/9N9Q0zdsCHXIKG0Q= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1774861887818928.933645332345; Mon, 30 Mar 2026 02:11:27 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1w78eO-0006Wb-WC; Mon, 30 Mar 2026 05:11:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w78e2-0006EW-Nt for qemu-devel@nongnu.org; Mon, 30 Mar 2026 05:10:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w78e1-0000Qd-7t for qemu-devel@nongnu.org; Mon, 30 Mar 2026 05:10:50 -0400 Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-540-dfcDTA4NNOeE5keocY1m2w-1; Mon, 30 Mar 2026 05:10:44 -0400 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 851451944B13; Mon, 30 Mar 2026 09:10:43 +0000 (UTC) Received: from S2.redhat.com (unknown [10.72.112.39]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 44B2319560B1; Mon, 30 Mar 2026 09:10:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774861848; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UIjxUX2mjHNiOeF8MWR0J6MRSnLuzQeAzy0f09dGBzM=; b=KkRxtZcTsR827KA28SmbegKweBCZNogA+TgXuBWsvIt1vQ0ZGn/EqZXlEI4zvqbwEOakcl RtPWPpP0nDYtuqRVZaeetZAcoqUnoA5WAHwwdCdO45MWE3r6UqBRY+UE/hY3dpd0By6kqZ NeZvjhnltC/eVvUA8JsxoRp++koBWzU= X-MC-Unique: dfcDTA4NNOeE5keocY1m2w-1 X-Mimecast-MFC-AGG-ID: dfcDTA4NNOeE5keocY1m2w_1774861843 From: Cindy Lu To: lulu@redhat.com, mst@redhat.com, jasowang@redhat.com, zhangckid@gmail.com, lizhijian@fujitsu.com, jmarcin@redhat.com, qemu-devel@nongnu.org Subject: [RFC v3 7/7] net/filter-redirector: check CAP_NET_RAW before creating AF_PACKET Date: Mon, 30 Mar 2026 16:58:15 +0800 Message-ID: <20260330090944.1008027-8-lulu@redhat.com> In-Reply-To: <20260330090944.1008027-1-lulu@redhat.com> References: <20260330090944.1008027-1-lulu@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.133.124; envelope-from=lulu@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 27 X-Spam_score: 2.7 X-Spam_bar: ++ X-Spam_report: (2.7 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.54, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_SBL_CSS=3.335, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=1, RCVD_IN_VALIDITY_RPBL_BLOCKED=1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1774861889234158500 Content-Type: text/plain; charset="utf-8" Creating an AF_PACKET SOCK_RAW socket requires the CAP_NET_RAW capability. Without it the qemu_socket() call fails with EPERM, producing a generic error that gives no hint about the missing capability. Add an explicit capget()-based check in filter_redirector_netdev_setup() before the socket call. Signed-off-by: Cindy Lu --- net/filter-mirror.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/net/filter-mirror.c b/net/filter-mirror.c index 165a7ee1ea..a521eec02b 100644 --- a/net/filter-mirror.c +++ b/net/filter-mirror.c @@ -34,6 +34,8 @@ #include #include #include +#include +#include =20 typedef struct MirrorState MirrorState; DECLARE_INSTANCE_CHECKER(MirrorState, FILTER_MIRROR, @@ -579,6 +581,21 @@ static void filter_redirector_maybe_enable_read_poll(N= etFilterState *nf) } } =20 +static bool filter_redirector_has_cap_net_raw(void) +{ + struct __user_cap_header_struct hdr =3D { + .version =3D _LINUX_CAPABILITY_VERSION_3, + .pid =3D 0, + }; + struct __user_cap_data_struct data[2] =3D {}; + + if (syscall(SYS_capget, &hdr, data) < 0) { + return false; + } + + return data[CAP_NET_RAW >> 5].effective & (1u << (CAP_NET_RAW & 31)); +} + static bool filter_redirector_netdev_setup(NetFilterState *nf, Error **err= p) { MirrorState *s =3D FILTER_REDIRECTOR(nf); @@ -615,6 +632,13 @@ static bool filter_redirector_netdev_setup(NetFilterSt= ate *nf, Error **errp) return false; } =20 + if (!filter_redirector_has_cap_net_raw()) { + error_setg(errp, + "AF_PACKET raw socket requires CAP_NET_RAW; " + "run with 'setcap cap_net_raw+ep ' or as r= oot"); + return false; + } + fd =3D qemu_socket(AF_PACKET, SOCK_RAW | SOCK_NONBLOCK, htons(ETH_P_AL= L)); if (fd < 0) { error_setg_errno(errp, errno, "failed to create AF_PACKET socket"); --=20 2.52.0