On August 13, 2024 10:42 am, Fiona Ebner wrote:
> 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.eb...@proxmox.com>
> ---
>
> Changes in v2:
> * rule out '../' in path
>
> PVE/QemuMigrate.pm | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/PVE/QemuMigrate.pm b/PVE/QemuMigrate.pm
> index e71face4..d31589e7 100644
> --- a/PVE/QemuMigrate.pm
> +++ b/PVE/QemuMigrate.pm
> @@ -1095,7 +1095,10 @@ sub phase2 {
> die "only UNIX sockets are supported for remote migration\n"
> if $tunnel_info->{proto} ne 'unix';
>
> - my $remote_socket = $tunnel_info->{addr};
> + # untaint
> + my ($remote_socket) =
> + $tunnel_info->{addr} =~
> m|^(/run/qemu-server/(?:(?!\.\./).)+\.migrate)$|;
should we just switch to `\d+`, like we do for regular migration? in
phase2_start_local_cluster we have:
elsif ($line =~ m!^migration listens on
(unix):(/run/qemu-server/(\d+)\.migrate)$!) {
$tunnel_info->{addr} = $2;
die "Destination UNIX sockets VMID does not match source VMID" if
$vmid ne $3;
$tunnel_info->{proto} = $1;
}
and I don't really see a reason to deviate from that scheme any time
soon?
> + die "unexpected socket address '$tunnel_info->{addr}'\n" if
> !$remote_socket;
> my $local_socket = $remote_socket;
> $local_socket =~ s/$remote_vmid/$vmid/g;
> $tunnel_info->{addr} = $local_socket;
> @@ -1104,6 +1107,9 @@ sub phase2 {
> PVE::Tunnel::forward_unix_socket($self->{tunnel}, $local_socket,
> $remote_socket);
>
> foreach my $remote_socket (@{$tunnel_info->{unix_sockets}}) {
> + # untaint
> + ($remote_socket) = $remote_socket =~
> m|^(/run/qemu-server/(?:(?!\.\./).)+\.migrate)$|
> + 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
>
>
>
_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
