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authorMarc Zyngier <marc.zyngier@arm.com>2018-09-27 16:53:22 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-10-03 17:01:00 -0700
commitfcaca557760f4fd78e793d8bfc4364fb58d7fb85 (patch)
tree9eb6a28c758f961c20481b4ccee918b003288e9b
parent4fff53acff152dcdf5d8758e273847f28c3b8e46 (diff)
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arm64: KVM: Sanitize PSTATE.M when being set from userspace
commit 2a3f93459d689d990b3ecfbe782fec89b97d3279 upstream. 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: 0d854a60b1d7 ("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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/arm64/include/asm/kvm_emulate.h5
-rw-r--r--arch/arm64/kvm/guest.c10
2 files changed, 14 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index e5df3fce0008..2b55aee7c051 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -42,6 +42,11 @@ void kvm_inject_vabt(struct kvm_vcpu *vcpu);
void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr);
void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr);
+static inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
+{
+ return !(vcpu->arch.hcr_el2 & HCR_RW);
+}
+
static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 3f4817dd69ae..76d27edf33cb 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -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) & COMPAT_PSR_MODE_MASK;
+ u64 mode = (*(u64 *)valp) & COMPAT_PSR_MODE_MASK;
switch (mode) {
case COMPAT_PSR_MODE_USR:
+ if (!system_supports_32bit_el0())
+ return -EINVAL;
+ break;
case COMPAT_PSR_MODE_FIQ:
case COMPAT_PSR_MODE_IRQ:
case COMPAT_PSR_MODE_SVC:
case COMPAT_PSR_MODE_ABT:
case COMPAT_PSR_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;