Skylake
Skylake
Posted Jan 16, 2018 11:44 UTC (Tue) by dwmw2 (subscriber, #2063)Parent article: Meltdown/Spectre mitigation for 4.15 and beyond
"The remaining concern on Skylake processors would appear to be system-management interrupts (SMIs), which can cause unprotected code to be run in kernel context. There does not appear to be a consensus that SMIs are exploitable in the real world, though, and no known proofs of the concept."The SMI thing is just one of a litany of conditions which on Skylake+ may cause the RSB to underflow, causing dangerous predictions to be taken from the branch predictor instead. There are many of those conditions which, individually, may have caused my to throw my toys out of the pram and say "Skylake+ gets IBRS". Including the one about deep call stacks of ≥16 in depth. How long did we spend playing whack-a-mole trying to make 4KiB stacks work? And that was when we got a nice clean crash with a stack overflow, not a silent vulnerability...