arm/arm64: KVM: Fix ioctl error handling

[ Upstream commit 4cad67fca3fc952d6f2ed9e799621f07666a560f ]

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.

Cc: stable@vger.kernel.org
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: Sasha Levin <sasha.levin@oracle.com>

diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index 8c97208b9b970c4d799e76ee7096d58dfb8c33ae..be68848071fd450325a232c4c5c039577d65a2bd 100644 (file)
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -173,7 +173,7 @@ 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 84d5959ff8742b64d37af40046a1c4fc8bd6e641..61ec16bd528bcc0d93186eaa63f6dc66b8adb31f 100644 (file)
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -184,7 +184,7 @@ 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;
 }
 
 /**