From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <pve-devel-bounces@lists.proxmox.com>
Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68])
	by lore.proxmox.com (Postfix) with ESMTPS id 76DFD1FF15E
	for <inbox@lore.proxmox.com>; Fri,  9 Aug 2024 12:17:40 +0200 (CEST)
Received: from firstgate.proxmox.com (localhost [127.0.0.1])
	by firstgate.proxmox.com (Proxmox) with ESMTP id BEE493BDF3;
	Fri,  9 Aug 2024 12:17:49 +0200 (CEST)
From: Fiona Ebner <f.ebner@proxmox.com>
To: pve-devel@lists.proxmox.com
Date: Fri,  9 Aug 2024 12:17:12 +0200
Message-Id: <20240809101712.37212-1-f.ebner@proxmox.com>
X-Mailer: git-send-email 2.39.2
MIME-Version: 1.0
X-SPAM-LEVEL: Spam detection results:  0
 AWL -0.059 Adjusted score from AWL reputation of From: address
 BAYES_00                 -1.9 Bayes spam probability is 0 to 1%
 DMARC_MISSING             0.1 Missing DMARC policy
 KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment
 RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to
 Validity was blocked. See
 https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more
 information.
 RCVD_IN_VALIDITY_RPBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to
 Validity was blocked. See
 https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more
 information.
 RCVD_IN_VALIDITY_SAFE_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to
 Validity was blocked. See
 https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more
 information.
 SPF_HELO_NONE           0.001 SPF: HELO does not publish an SPF Record
 SPF_PASS               -0.001 SPF: sender matches SPF record
 URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See
 http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more
 information. [qemumigrate.pm, proxmox.com]
Subject: [pve-devel] [PATCH qemu-server] remote migration: fix online
 migration via API clients
X-BeenThere: pve-devel@lists.proxmox.com
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Proxmox VE development discussion <pve-devel.lists.proxmox.com>
List-Unsubscribe: <https://lists.proxmox.com/cgi-bin/mailman/options/pve-devel>, 
 <mailto:pve-devel-request@lists.proxmox.com?subject=unsubscribe>
List-Archive: <http://lists.proxmox.com/pipermail/pve-devel/>
List-Post: <mailto:pve-devel@lists.proxmox.com>
List-Help: <mailto:pve-devel-request@lists.proxmox.com?subject=help>
List-Subscribe: <https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel>, 
 <mailto:pve-devel-request@lists.proxmox.com?subject=subscribe>
Reply-To: Proxmox VE development discussion <pve-devel@lists.proxmox.com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: pve-devel-bounces@lists.proxmox.com
Sender: "pve-devel" <pve-devel-bounces@lists.proxmox.com>

As reported in the community forum [0], when a remote migration
request comes in via an API client, the -T flag for Perl is set, so an
insecure dependency in a call like unlink() in forward_unix_socket()
will fail with:

> failed to write forwarding command - Insecure dependency in unlink while running with -T switch

To fix it, untaint the problematic socket addresses coming from the
remote side. Require that all sockets are below '/run/qemu-server/'
and end with '.migrate'. This allows extensions in the future while
still being quite strict.

[0]: https://forum.proxmox.com/threads/123048/post-691958

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---

There is no direct call to forward_unix_socket() in pve-container and
the call in PVE::StorageTunnel::storage_migrate() has no insecure
dependency for the local socket path.

 PVE/QemuMigrate.pm | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/PVE/QemuMigrate.pm b/PVE/QemuMigrate.pm
index e71face4..7a7183e0 100644
--- a/PVE/QemuMigrate.pm
+++ b/PVE/QemuMigrate.pm
@@ -1095,7 +1095,8 @@ sub phase2 {
 	die "only UNIX sockets are supported for remote migration\n"
 	    if $tunnel_info->{proto} ne 'unix';
 
-	my $remote_socket = $tunnel_info->{addr};
+	my ($remote_socket) = $tunnel_info->{addr} =~ m!^(/run/qemu-server/.*\.migrate)$! #untaint
+	    or die "unexpected socket address '$tunnel_info->{addr}'\n";
 	my $local_socket = $remote_socket;
 	$local_socket =~ s/$remote_vmid/$vmid/g;
 	$tunnel_info->{addr} = $local_socket;
@@ -1104,6 +1105,8 @@ sub phase2 {
 	PVE::Tunnel::forward_unix_socket($self->{tunnel}, $local_socket, $remote_socket);
 
 	foreach my $remote_socket (@{$tunnel_info->{unix_sockets}}) {
+	    ($remote_socket) = $remote_socket =~ m!^(/run/qemu-server/.*\.migrate)$! # untaint
+		or die "unexpected socket address '$remote_socket'\n";
 	    my $local_socket = $remote_socket;
 	    $local_socket =~ s/$remote_vmid/$vmid/g;
 	    next if $self->{tunnel}->{forwarded}->{$local_socket};
-- 
2.39.2



_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel