arm64: KVM: Fix user access for debug registers
When setting the debug register from userspace, make sure that
copy_from_user() is called with its parameters in the expected
order. It otherwise doesn't do what you think.
Fixes: 84e690bfbed1 ("KVM: arm64: introduce vcpu->arch.debug_ptr")
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Cc: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index b41607d..1d0463e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -272,7 +272,7 @@
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
- if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
+ if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
@@ -314,7 +314,7 @@
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg];
- if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
+ if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
@@ -358,7 +358,7 @@
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg];
- if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
+ if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
@@ -400,7 +400,7 @@
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg];
- if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
+ if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}