arm/arm64: KVM: Fix ioctl error handling

commit 4cad67fca3fc952d6f2ed9e799621f07666a560f upstream.

Calling return copy_to_user(...) in an ioctl will not
do the right thing if there's a pagefault:
copy_to_user returns the number of bytes not copied
in this case.

Fix up kvm to do
	return copy_to_user(...)) ?  -EFAULT : 0;

everywhere.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index 96e935bbc38c8b4fd906aeacdc27ca28696b596a..3705fc2921c2ddf6a3e33526703183b248521f7a 100644 (file)
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -155,7 +155,7 @@ static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
        u64 val;
 
        val = kvm_arm_timer_get_reg(vcpu, reg->id);
-       return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id));
+       return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
 }
 
 static unsigned long num_core_regs(void)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index d250160d32bc68ae636c804b9cdfe2499bdddcb9..3039f080e2d5820ed4446aac0871dee42ffa5ad2 100644 (file)
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -186,7 +186,7 @@ static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
        u64 val;
 
        val = kvm_arm_timer_get_reg(vcpu, reg->id);
-       return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id));
+       return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
 }
 
 /**