Commit 2a3f9345 authored Sep 27, 2018 by Marc Zyngier Committed by Will Deacon Oct 01, 2018

arm64: KVM: Sanitize PSTATE.M when being set from userspace



Not all execution modes are valid for a guest, and some of them
depend on what the HW actually supports. Let's verify that what
userspace provides is compatible with both the VM settings and
the HW capabilities.

Cc: <stable@vger.kernel.org>
Fixes: 0d854a60 ("arm64: KVM: enable initialization of a 32bit vcpu")
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

parent d26c25a9

arch/arm64/kvm/guest.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -152,17 +152,25 @@ static int set_core_reg(struct kvm_vcpu vcpu, const struct kvm_one_reg reg)
		}

		if (off == KVM_REG_ARM_CORE_REG(regs.pstate)) {
		u32 mode = ((u32 )valp) & PSR_AA32_MODE_MASK;
		u64 mode = ((u64 )valp) & PSR_AA32_MODE_MASK;
		switch (mode) {
		case PSR_AA32_MODE_USR:
		if (!system_supports_32bit_el0())
		return -EINVAL;
		break;
		case PSR_AA32_MODE_FIQ:
		case PSR_AA32_MODE_IRQ:
		case PSR_AA32_MODE_SVC:
		case PSR_AA32_MODE_ABT:
		case PSR_AA32_MODE_UND:
		if (!vcpu_el1_is_32bit(vcpu))
		return -EINVAL;
		break;
		case PSR_MODE_EL0t:
		case PSR_MODE_EL1t:
		case PSR_MODE_EL1h:
		if (vcpu_el1_is_32bit(vcpu))
		return -EINVAL;
		break;
		default:
		err = -EINVAL;