5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Christopherson <seanjc@xxxxxxxxxx> commit 5d6c7de6446e9ab3fb41d6f7d82770e50998f3de upstream. Exit to userspace when emulating an atomic guest access if the CMPXCHG on the userspace address faults. Emulating the access as a write and thus likely treating it as emulated MMIO is wrong, as KVM has already confirmed there is a valid, writable memslot. Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> Message-Id: <20220202004945.2540433-6-seanjc@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7108,7 +7108,7 @@ static int emulator_cmpxchg_emulated(str } if (r < 0) - goto emul_write; + return X86EMUL_UNHANDLEABLE; if (r) return X86EMUL_CMPXCHG_FAILED;
