[PATCH v6 06/10] x86/alternative: use temporary mm for text poking

2018-11-20 Thread Nadav Amit
text_poke() can potentially compromise the security as it sets temporary PTEs in the fixmap. These PTEs might be used to rewrite the kernel code from other cores accidentally or maliciously, if an attacker gains the ability to write onto kernel memory. Moreover, since remote TLBs are not flushed

[PATCH v6 06/10] x86/alternative: use temporary mm for text poking

2018-11-20 Thread Nadav Amit
text_poke() can potentially compromise the security as it sets temporary PTEs in the fixmap. These PTEs might be used to rewrite the kernel code from other cores accidentally or maliciously, if an attacker gains the ability to write onto kernel memory. Moreover, since remote TLBs are not flushed