From: Maxim Levitsky mlevitsk@redhat.com
commit 5015bb89b58225f97df6ac44383e7e8c8662c8c9 upstream.
SYSEXIT is one of the instructions that can change the processor mode, thus ctxt->mode should be updated after it.
Note that this is likely a benign bug, because the only problematic mode change is from 32 bit to 64 bit which can lead to truncation of RIP, and it is not possible to do with sysexit, since sysexit running in 32 bit mode will be limited to 32 bit version.
Signed-off-by: Maxim Levitsky mlevitsk@redhat.com Message-Id: 20221025124741.228045-11-mlevitsk@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/emulate.c | 1 + 1 file changed, 1 insertion(+)
--- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2895,6 +2895,7 @@ static int em_sysexit(struct x86_emulate ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
ctxt->_eip = rdx; + ctxt->mode = usermode; *reg_write(ctxt, VCPU_REGS_RSP) = rcx;
return X86EMUL_CONTINUE;