Speculative Execution Vulnerabilities of 2018
In January of 2018, news of three speculative execution vulnerabilities was made public. Information about these vulnerabilities had been disclosed in private to certain companies and projects in June of 2016.
|CVE||Group||Google Project Zero name|
|CVE-2017-5715||Spectre||Variant 2: branch target injection|
|CVE-2017-5753||Spectre||Variant 1: bounds check bypass|
|CVE-2017-5754||Meltdown||Variant 3: rogue data cache load|
POWER7, POWER8, and POWER9 are patched from CVE-2017-5754 by purging the L1 cache when context switching to a less privileged process, as the vulnerability on these architectures affects L1 but not L2 cache. Firmware updates are also required to enable workarounds at the hardware level. .
CVE-2017-5753 (Spectre variant 1)
Hardware fixes are in place for POWER9 Nimbus DD2.2 / Cumulus DD1.1 and above . With these hardware changes, cross-process attacks via Spectre variant 1 are believed to be fully mitigated on the production POWER9 devices.
CVE-2017-5715 (Spectre variant 2)
Official statement from Raptor Computing Systems regarding Talos™ II
POWER9 will not ship with vulnerability to Meltdown or any loss in performance compared with the current prototype chips (DD2.1). Further, Spectre is fully mitigated with the exception of the same-process issue that is affecting the entire CPU industry. As far as we are aware there will be no further mitigation from any major CPU vendor now or in the future, as the remaining Spectre issue has been deemed an application level programming issue versus a CPU design issue. Patches for GCC to help fix the affected applications are already rolling out.
- Reading privileged memory with a side-channel. Project Zero blog
- IBM PSIRT Blog post, Potential Impact on Processors in the POWER family
- TenFourFox Development blog post, Actual field testing of Spectre on various Power Macs
- Raptor Engineering GNU Social notices about POWER8 and POWER9 vulnerability
- Red Hat security page for Kernel Side-Channel Attacks
- Larabel, Michael. PowerPC Memory Protection Keys In For Linux 4.16, Power Has Meltdown Mitigation In 4.15. 2018-01-22
- IBM Power8 Systems Server Firmware
- IBM POWER9 Systems Server Firmware
- Hostboot commit message listing security changes for NDD2.2 / CDD1.1