From e3ef461af35a8c74f2f4ce6616491ddb355a208f Mon Sep 17 00:00:00 2001 From: "Borislav Petkov (AMD)" Date: Fri, 5 Jan 2024 11:14:07 +0100 Subject: x86/sev: Harden #VC instruction emulation somewhat Compare the opcode bytes at rIP for each #VC exit reason to verify the instruction which raised the #VC exception is actually the right one. Signed-off-by: Borislav Petkov (AMD) Acked-by: Tom Lendacky Link: https://lore.kernel.org/r/20240105101407.11694-1-bp@alien8.de --- arch/x86/boot/compressed/sev.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/x86/boot/compressed') diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index 454acd7a2daf..073291832f44 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -304,6 +304,10 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code) if (result != ES_OK) goto finish; + result = vc_check_opcode_bytes(&ctxt, exit_code); + if (result != ES_OK) + goto finish; + switch (exit_code) { case SVM_EXIT_RDTSC: case SVM_EXIT_RDTSCP: -- cgit v1.2.3