From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DA9BE542EE8 for ; Tue, 22 Sep 2026 12:49:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790081391; cv=none; b=mO+vPCogMwjzJaaluWE2R8JTS7DFAXMFFbe6/H/w8dpvRZ0YmDa9WYvywgFZ2brqEO7RAPSLXa1dKWIvjLbK6pCkOR9PjZ8sIa1pk/vDIGpxUKrOj4jgKjFALB3km5hTgN8/TP3ECein74X8kIvt1AUHzss3tgrz/n7beAdQ1ko= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790081391; c=relaxed/simple; bh=H77B/1XoUbsQHeqCDGjv35YwEIvkYUiwrSWHUSL0kKQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: In-Reply-To:Content-Type:Content-Disposition; b=DnTg7jpBqGVIeYLmkVU/f5F/sg4SZQmxX0HwGi3bZVwkX/UDm4q2PI4SZNGtG00YKOwYGqTShnJTrfD3p4g8z6HpTMWULIh6hb41Y6FPCA9Hd355CxCropnsvOCg39UvS21tKE7XhWmCCJ108odqrwsWhCThU4PdjlqkYiy+DQ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=WcxqrO7G; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WcxqrO7G" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1790081389; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BMtW18PYGgs3eeFoZyurBYg14pG+Ej8vE9R6o+NDZ70=; b=WcxqrO7GlSnu9cGv7lANg2I3/8zqjVz9vy9YjKmpm2P3v6FM87VkLIt5q5zUuUEiwcoYbk hgok/Mudple2xDuhqT2MXrzTlfmeE8yj3wAHSVuFl7pXQENeouB1U1y2j5h9l3fDNR6XF1 Xx91pAKRA3Tj73SYvoUkcz9jlPkV4nA= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-646-M9gtmOyLMGKJ-QQ99vzOaA-1; Tue, 22 Sep 2026 08:49:47 -0400 X-MC-Unique: M9gtmOyLMGKJ-QQ99vzOaA-1 X-Mimecast-MFC-AGG-ID: M9gtmOyLMGKJ-QQ99vzOaA_1790081386 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-485866e0066so1317451f8f.2 for ; Tue, 22 Sep 2026 05:49:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790081386; x=1790686186; h=in-reply-to:content-transfer-encoding:content-disposition :content-type:mime-version:references:message-id:subject:cc:to:from :date:x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=BMtW18PYGgs3eeFoZyurBYg14pG+Ej8vE9R6o+NDZ70=; b=EDMHUCHK3YRNyhog0W/fPJipvHauNv7Ig8xSxQTAG7nGJFlMzvDiDIrTeaNRKtfiUw 0TjDsl3TY2+xl/xMtsA0OAM91uLWs7MnSoNLspPK9jPiyQYfLZqa5xJ/BldXiwezEGPj faWLLWn38sRmN/JT8qI743Cb3LukbjdpNYeh/bcAhlCgLITpu4UIFWEcdTlXx8hk4eLS +aeSV33owO5uVdF0Cj4Q0O5R8bZCEckBi/uqLqZ3xP84y+Ar3tPt3ixHQON7BfsCvy1w 2YaV3QVSy3qF0E7xmCmJTi/8JY9hkELnvk7Ch2xl0ZV88Bh0P5QSTgFIZoYxFUaeiQrU jTLg== X-Forwarded-Encrypted: i=1; AKwUvBzo11Iyx6PIsXEHvR8EXS2f/nh4/DS2DntF0XWR8TGVZ1mbksSuRicAlK7ddnmMUnpBgHWj5EkCPgOa5msvbg==@lists.linux.dev X-Gm-Message-State: AFuF++mA5zRbhK4R69OTYSWleG7werzPfHhSlOIF9mMAH3GNiF23Y2oW HcUiUcXMT5icqkMF6NQuYCVz3FLx0i3LIIdo88Hlx8ujOUif1ql2PDbQlsxBDDV3XrG9uF2ncQH GW8NiT39ium79G4kdXZolgtx5wqlp5JjCIqSONq9wW24Bps0cv/aW+nnjR/RzWjfZONhH X-Gm-Gg: AYBFou01eu6tukqBFCj8DqXh62vh4QEdFNQ1coxV9oLUQwAlGSAQaM4/AKe5LsLcjZU 9kwgyUuJPapLG9WdwRypPnamR7yPZv1aleqdUBks8GOCxwYGhhyFK2jc17HWeze9OslEstreuoB CnV30DvP0s81c0FoOCylQX/RQiVHtsJb2DbmJIe6zxRx5Qz0mydaDEiZrUezjRdhVM7fklee+N8 R344bJOL8LVDygWXMutBickqSmKnLSSvii7NFlstvRdyFCjV0cT1Qzwkt8SWHHCh0hBCsXX9ikp mymrtpWDbM0HVCiqAGdCMzaqNb0NVaXTYR/Qzs7VQSTKfzcB9RDWqaxGkcWjVE6VnpZ0QCYVJgn dQJl56vECkXOMpRwPsGm3I5Wa4FSuRkfGCLmL9Aa4VoInWwaw43I= X-Received: by 2002:adf:e19a:0:b0:486:fba3:b95d with SMTP id ffacd0b85a97d-4871e2161fbmr20532326f8f.7.1790081385750; Tue, 22 Sep 2026 05:49:45 -0700 (PDT) X-Received: by 2002:adf:e19a:0:b0:486:fba3:b95d with SMTP id ffacd0b85a97d-4871e2161fbmr20532296f8f.7.1790081385348; Tue, 22 Sep 2026 05:49:45 -0700 (PDT) Received: from sgarzare-redhat (host-82-53-134-131.retail.telecomitalia.it. [82.53.134.131]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48862774882sm5070366f8f.13.2026.09.22.05.49.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Sep 2026 05:49:44 -0700 (PDT) Date: Tue, 22 Sep 2026 14:49:34 +0200 From: Stefano Garzarella To: =?utf-8?Q?Bart=C5=82omiej?= Dmitruk Cc: Bryan Tan , Vishnu Dasa , bcm-kernel-feedback-list@broadcom.com, "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , "Michael S . Tsirkin" , virtualization@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/2] vsock/vmci: enforce per-netns mode on the datagram receive path Message-ID: References: <20260919123208.29032-1-bartlomiej.dmitruk@isec.pl> <20260919123208.29032-2-bartlomiej.dmitruk@isec.pl> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20260919123208.29032-2-bartlomiej.dmitruk@isec.pl> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: vH755REVmtrNfZ9JmiPN8NKoNQud-QgurIsIIsa8C_M_1790081386 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit On Sat, Sep 19, 2026 at 02:31:57PM +0200, Bartłomiej Dmitruk wrote: >The send hook vmci_transport_dgram_allow() refuses datagrams when the socket's >netns is not in global mode (vsock_net_mode_global()), but the receive path >(vmci_transport_recv_dgram_cb() -> vmci_transport_allow_dgram()) did not, so a >socket bound in a non-global (local) netns received datagrams from peers it >could never send to, defeating namespace isolation. > >Add the check at the start of the receive decision, before the >VMADDR_CID_HYPERVISOR short-circuit, so the hypervisor CID is covered too >(matching the send side). > >This was found by code inspection; I do not have VMCI hardware to test on >(compile-tested only). > >Fixes: eafb64f40ca4 ("vsock: add netns to vsock core") >Signed-off-by: Bartłomiej Dmitruk >Assisted-by: Claude (Anthropic) >--- >v2: perform the netns check first (before the hypervisor early return) so > hypervisor datagrams are also gated in local mode -- the Sashiko AI review > noted v1 left that path partially bypassed. >v1: https://lore.kernel.org/netdev/20260917220225.56200-1-bartlomiej.dmitruk@isec.pl/ > LGTM, but please add a cover letter to a series with multiple patches. Stefano >diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c >--- a/net/vmw_vsock/vmci_transport.c >+++ b/net/vmw_vsock/vmci_transport.c >@@ -532,6 +532,14 @@ > static bool vmci_transport_allow_dgram(struct vsock_sock *vsock, u32 peer_cid) > { > u64 access; >+ >+ /* Enforce the per-netns mode first, symmetrically with the send hook >+ * vmci_transport_dgram_allow(): a socket in a non-global (local) netns >+ * must not receive datagrams it could never send (this also covers the >+ * hypervisor CID). >+ */ >+ if (!vsock_net_mode_global(vsock)) >+ return false; > > if (VMADDR_CID_HYPERVISOR == peer_cid) > return true; >