| From | Jiri Slaby <> | Subject | [PATCH 3.12 101/122] KVM: x86: Sysexit emulation does not mask RIP/RSP | Date | Tue, 17 Feb 2015 12:34:48 +0100 |
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From: Nadav Amit <namit@cs.technion.ac.il>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit bf0b682c9b6a6d6d54adf439bfe953feef7be2e8 upstream.
If the operand size is not 64-bit, then the sysexit instruction should assign ECX to RSP and EDX to RIP. The current code assigns the full 64-bits.
Fix it by masking.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- arch/x86/kvm/emulate.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index d28104924255..8ab43ac68f06 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2372,6 +2372,8 @@ static int em_sysexit(struct x86_emulate_ctxt *ctxt) if ((msr_data & 0xfffc) == 0x0) return emulate_gp(ctxt, 0); ss_sel = (u16)(msr_data + 24); + rcx = (u32)rcx; + rdx = (u32)rdx; break; case X86EMUL_MODE_PROT64: cs_sel = (u16)(msr_data + 32); -- 2.2.2
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