<html><body><p><font size="2">Hi Aaron,</font><br><br><font size="2">If cluster A uses the mmauth command to grant a file system read-only access to a remote cluster B, nodes on cluster B can only mount that file system with read-only access. But the only checking being done at the RPC level is the TLS authentication. This should prevent non-root users from initiating RPCs, since TLS authentication requires access to the local cluster's private key. However, a root user on cluster B, having access to cluster B's private key, might be able to craft RPCs that may allow one to work around the checks which are implemented at the file system level.</font><br><br><font size="2">Regards, The Spectrum Scale (GPFS) team<br><br>------------------------------------------------------------------------------------------------------------------<br>If you feel that your question can benefit other users of Spectrum Scale (GPFS), then please post it to the public IBM developerWroks Forum at <a href="https://www.ibm.com/developerworks/community/forums/html/forum?id=11111111-0000-0000-0000-000000000479">https://www.ibm.com/developerworks/community/forums/html/forum?id=11111111-0000-0000-0000-000000000479</a>. <br><br>If your query concerns a potential software error in Spectrum Scale (GPFS) and you have an IBM software maintenance contract please contact 1-800-237-5511 in the United States or your local IBM Service Center in other countries. <br><br>The forum is informally monitored as time permits and should not be used for priority messages to the Spectrum Scale (GPFS) team.</font><br><br><img width="16" height="16" src="cid:1__=0ABB0B14DFEFE2488f9e8a93df938690918c0AB@" border="0" alt="Inactive hide details for Aaron Knister ---08/21/2017 11:04:06 PM---Hi Everyone, I have a theoretical question about GPFS multi"><font size="2" color="#424282">Aaron Knister ---08/21/2017 11:04:06 PM---Hi Everyone, I have a theoretical question about GPFS multiclusters and security.</font><br><br><font size="2" color="#5F5F5F">From: </font><font size="2">Aaron Knister <aaron.s.knister@nasa.gov></font><br><font size="2" color="#5F5F5F">To: </font><font size="2">gpfsug main discussion list <gpfsug-discuss@spectrumscale.org></font><br><font size="2" color="#5F5F5F">Date: </font><font size="2">08/21/2017 11:04 PM</font><br><font size="2" color="#5F5F5F">Subject: </font><font size="2">[gpfsug-discuss] multicluster security</font><br><font size="2" color="#5F5F5F">Sent by: </font><font size="2">gpfsug-discuss-bounces@spectrumscale.org</font><br><hr width="100%" size="2" align="left" noshade style="color:#8091A5; "><br><br><br><tt><font size="2">Hi Everyone,<br><br>I have a theoretical question about GPFS multiclusters and security. <br>Let's say I have clusters A and B. Cluster A is exporting a filesystem <br>as read-only to cluster B.<br><br>Where does the authorization burden lay? Meaning, does the security rely <br>on mmfsd in cluster B to behave itself and enforce the conditions of the <br>multi-cluster export? Could someone using the credentials on a <br>compromised node in cluster B just start sending arbitrary nsd <br>read/write commands to the nsds from cluster A (or something along those <br>lines)? Do the NSD servers in cluster A do any sort of sanity or <br>security checking on the I/O requests coming from cluster B to the NSDs <br>they're serving to exported filesystems?<br><br>I imagine any enforcement would go out the window with shared disks in a <br>multi-cluster environment since a compromised node could just "dd" over <br>the LUNs.<br><br>Thanks!<br><br>-Aaron<br><br>-- <br>Aaron Knister<br>NASA Center for Climate Simulation (Code 606.2)<br>Goddard Space Flight Center<br>(301) 286-2776<br>_______________________________________________<br>gpfsug-discuss mailing list<br>gpfsug-discuss at spectrumscale.org<br></font></tt><tt><font size="2"><a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__gpfsug.org_mailman_listinfo_gpfsug-2Ddiscuss&d=DwICAg&c=jf_iaSHvJObTbx-siA1ZOg&r=IbxtjdkPAM2Sbon4Lbbi4w&m=oK_bEPbjuD7j6qLTHbe7HM4ujUlpcNYtX3tMW2QC7_w&s=BliMQ0pToLIIiO1jfyUp2Q3icewcONrcmHpsIj_hMtY&e=">https://urldefense.proofpoint.com/v2/url?u=http-3A__gpfsug.org_mailman_listinfo_gpfsug-2Ddiscuss&d=DwICAg&c=jf_iaSHvJObTbx-siA1ZOg&r=IbxtjdkPAM2Sbon4Lbbi4w&m=oK_bEPbjuD7j6qLTHbe7HM4ujUlpcNYtX3tMW2QC7_w&s=BliMQ0pToLIIiO1jfyUp2Q3icewcONrcmHpsIj_hMtY&e=</a></font></tt><tt><font size="2"> <br><br></font></tt><br><br><BR>
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