[pve-devel] [PATCH storage] ZFSPlugin: untaint lun number

[Daniel Berteaud]

----- Le 9 Oct 20, à 17:26, Daniel Berteaud daniel at firewall-services.com a écrit :

> ----- Le 9 Oct 20, à 17:13, Stoiko Ivanov s.ivanov at proxmox.com a écrit :
> 
>> ZFS over iSCSI fetches information about the disk-images via ssh, thus
>> the obtainted data is tainted (perlsec (1)).
>> 
>> Since pvedaemon runs with '-T' enabled trying to start a VM via GUI/API failed,
>> while it still worked via `qm` or `pvesh`.
>> 
>> The issue surfaced after commit cb9db10c1a9855cf40ff13e81f9dd97d6a9b2698 in
>> pve-common ('run_command: improve performance for logging and long lines'),
>> and results from concatenating the original (tainted) buffer to a variable,
>> instead of a captured subgroup.
>> 
>> Untainting the value in ZFSPlugin should not cause any regressiosn, since the
>> other 3 target providers already have a match on '\d+' for retrieving the
>> lun number.
>> 
>> reported via pve-user [0].
>> 
>> reproduced and tested by setting up a LIO-target (on top of a virtual PVE),
>> adding it as storage and trying to start a guest (with a disk on the
>> ZFS over iSCSI storage) with `perl -T /usr/sbin/qm start $vmid`
>> 
>> [0] https://lists.proxmox.com/pipermail/pve-user/2020-October/172055.html
>> 
>> Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
>> ---
>> PVE/Storage/ZFSPlugin.pm | 6 +++++-
>> 1 file changed, 5 insertions(+), 1 deletion(-)
>> 
>> diff --git a/PVE/Storage/ZFSPlugin.pm b/PVE/Storage/ZFSPlugin.pm
>> index 383f0a0..63b9551 100644
>> --- a/PVE/Storage/ZFSPlugin.pm
>> +++ b/PVE/Storage/ZFSPlugin.pm
>> @@ -159,7 +159,11 @@ sub zfs_get_lun_number {
>> 
>>     die "could not find lun_number for guid $guid" if !$guid;
>> 
>> -    return $class->zfs_request($scfg, undef, 'list_view', $guid);
>> +    if ($class->zfs_request($scfg, undef, 'list_view', $guid) =~ /^(\d+)$/) {
>> +	return $1;
>> +    }
>> +
>> +    die "lun_number for guid $guid is not a number";
>> }
> 


I can confirm this is fixing the issue of the VM not starting from the web interface. There's still a (probably) related issue : ZFS over iSCSI disks can't be removed (eg, at the end of a live disk move) :

Use of uninitialized value in die at /usr/share/perl5/PVE/Storage/LunCmd/LIO.pm line 337.
error during cfs-locked 'storage-iscsi-zfs-zol1-prd' operation: command '/usr/bin/ssh -o 'BatchMode=yes' -i /etc/pve/priv/zfs/10.29.255.252_id_rsa root at 10.29.255.252 -- /usr/bin/targetcli /iscsi/iqn.2019-10.fr.fws.pve:prod/tpg1/luns/ delete lun1' failed: Insecure dependency in exec while running with -T switch at /usr/share/perl/5.28/IPC/Open3.pm line 178.
	...propagated at /usr/share/perl5/PVE/Storage/LunCmd/LIO.pm line 337.

It might be only affecting the LIO backend though

Cheers,
Daniel


-- 
[ https://www.firewall-services.com/ ] 	
Daniel Berteaud 
FIREWALL-SERVICES SAS, La sécurité des réseaux 
Société de Services en Logiciels Libres 
Tél : +33.5 56 64 15 32 
Matrix: @dani:fws.fr 
[ https://www.firewall-services.com/ | https://www.firewall-services.com ]