From c8a2fd7a715d9882eed5ddb4105bce2f6a8163c2 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Tue, 25 Oct 2022 15:47:28 +0300 Subject: [PATCH] KVM: x86: emulator: em_sysexit should update ctxt->mode 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 Message-Id: <20221025124741.228045-11-mlevitsk@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/emulate.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 52a881d24070..8404d5d00bf3 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2957,6 +2957,7 @@ static int em_sysexit(struct x86_emulate_ctxt *ctxt) 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;