Best posts made by olivierlambert

Since last week, we have a new team member @ronan-a is now part of Vates XCP-ng team, with @stormi and myself.

@r1 and @johnelse are still with us as external contributors.

@ronan-a , feel free to introduce yourself here (and the stuff you are working on)

Hey guys!

Just before the official announcement tomorrow, please double test our latest ISO: https://xcp-ng.org/7.5/xcp-ng-7.5.0.iso

md5sum: 33adb5d92f56fe6cda0df047f2f60895

Nothing really changed since RC1 (except very few stuff).

A bunch of Xen security issues are now public after the usual embargo.

Note: website to check all XSA's is https://xenbits.xen.org/xsa/

XSA 294: insufficient TLB flushing

The major/most visible flaw (XSA 294)was related to a host crash triggered by a PV guest. Some users (@borzel for example), reported it here: https://xcp-ng.org/forum/topic/1025/host-crash-guest_4-o-sh_page_fault__guest 64 bits PV guests are affected.

Note: boot your host with the "pcid=0" parameter. This will likely have an impact on performance but should avoid the crash.

However, it was before the end of the embargo, so we can't comment and release a patch before it's known publicly.

Patched Xen will be available in the usual update channel as soon we got something tested and validated.

Others

The list of other new XSA's are:

• XSA 293: 64 bits PV guests can crash or be used for privilege escalation
• XSA 292: PV guests could cause a host crash or access data of other guests (similar to XSA 294)
• XSA 291: PV guests could cause a DDOS on the host via IOMMU
• XSA 290: PV guests could cause a DDOS on the hostto XSA 294)

All those vuln will be patched in the next Xen update. Stay tuned!