api2: osd destroy: untaint device before pvremove

We get the device list from ceph-volume lvm list, and decode the json
output, which at that point is tainted (perlsec (1)).
Untaint it here before calling, because it is currently the only
call-site using the information in a problematic way (run_command).
(the only other call-site being in pve5to6)

Alternatively we could untaint while reading the information, but then
should only return a small subset of the ceph-volume output.

The issue is most likely due to
cb9db10c1a9855cf40ff13e81f9dd97d6a9b2698 in pve-common ('run_command:
improve performance for logging and long lines'),

Tested on a virtual testsetup by creating OSDs with second DB disk,
and destroying it via GUI (did not manage to get the error without the
DB disk)

Reported via our community forum:
https://forum.proxmox.com/threads/insecure-dependency-in-exec-during-osd-destroy.79574/

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>

PVE/API2/Ceph/OSD.pm

@@ -575,6 +575,8 @@ __PACKAGE__->register_method ({
 		    # try to remove pvs, but do not fail if it does not work
 		    for my $osd_part (@{$osd_list->{$osdid}}) {
 			for my $dev (@{$osd_part->{devices}}) {
+			    ($dev) = ($dev =~ m|^(/dev/[-_.a-zA-Z0-9\/]+)$|); #untaint
+
 			    eval { run_command(['/sbin/pvremove', $dev], errfunc => sub {}) };
 			    warn $@ if $@;
 			}