4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michael S. Tsirkin <m...@redhat.com>
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.d...@linaro.org>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/arm/kvm/guest.c | 2 +-
arch/arm64/kvm/guest.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -155,7 +155,7 @@ static int get_timer_reg(struct kvm_vcpu
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)
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -186,7 +186,7 @@ static int get_timer_reg(struct kvm_vcpu
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;
}
/**
