From: Joerg Roedel <jroe...@suse.de>
Hi,
here are some changes to the Linux SEV-ES code to check whether the
value in regs->sp can be trusted, before checking whether it points to
the #VC IST stack.
Andy Lutomirski reported that it is entirely possible to reach this
function with a regs->sp value which was set by user-space. So check
for this condition and don't use regs->sp if it can't be trusted.
Also improve the comments around __sev_es_ist_enter/exit() to better
explain what these function do and why they are there.
Please review.
Thanks,
Joerg
Joerg Roedel (3):
x86/sev-es: Introduce from_syscall_gap() helper
x86/sev-es: Check if regs->sp is trusted before adjusting #VC IST
stack
x86/sev-es: Improve comments in and around __sev_es_ist_enter/exit()
arch/x86/include/asm/ptrace.h | 8 ++++++++
arch/x86/kernel/sev-es.c | 27 +++++++++++++++++++--------
arch/x86/kernel/traps.c | 3 +--
3 files changed, 28 insertions(+), 10 deletions(-)
--
2.30.0
