Re: [PATCH V3 1/6] x86_64: move cpu_current_top_of_stack out of TSS

2021-02-04 Thread Borislav Petkov
> Subject: Re: [PATCH V3 1/6] x86_64: move cpu_current_top_of_stack out of TSS The tip tree preferred format for patch subject prefixes is 'subsys/component:', e.g. 'x86/apic:', 'x86/mm/fault:', 'sched/fair:', 'genirq/core:'. Please do not use file names or complete file paths as prefix. 'git

[PATCH V3 1/6] x86_64: move cpu_current_top_of_stack out of TSS

2021-01-27 Thread Lai Jiangshan
From: Lai Jiangshan When X86_BUG_CPU_MELTDOWN & KPTI, cpu_current_top_of_stack lives in the TSS which is also in the user CR3 and it becomes a coveted fruit. An attacker can fetch the kernel stack top from it and continue next steps of actions based on the kernel stack. The address might not