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Shutemov" Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, x86@kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, Ira Weiny , Kai Huang , Binbin Wu , Michael Roth , Yan Zhao , Vishal Annapurve , Rick Edgecombe , Ackerley Tng Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a helper to copy a kvm_tdx_cmd structure from userspace and verify that must-be-zero fields are indeed zero. No functional change intended. Reviewed-by: Rick Edgecombe Reviewed-by: Kai Huang Signed-off-by: Sean Christopherson Reviewed-by: Binbin Wu --- arch/x86/kvm/vmx/tdx.c | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-) diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 97632fc6b520..390c934562c1 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -2782,20 +2782,29 @@ static int tdx_td_finalize(struct kvm *kvm, struct = kvm_tdx_cmd *cmd) return 0; } =20 +static int tdx_get_cmd(void __user *argp, struct kvm_tdx_cmd *cmd) +{ + if (copy_from_user(cmd, argp, sizeof(*cmd))) + return -EFAULT; + + /* + * Userspace should never set hw_error. KVM writes hw_error to report + * hardware-defined error back to userspace. + */ + if (cmd->hw_error) + return -EINVAL; + + return 0; +} + int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { struct kvm_tdx_cmd tdx_cmd; int r; =20 - if (copy_from_user(&tdx_cmd, argp, sizeof(struct kvm_tdx_cmd))) - return -EFAULT; - - /* - * Userspace should never set hw_error. It is used to fill - * hardware-defined error by the kernel. - */ - if (tdx_cmd.hw_error) - return -EINVAL; + r =3D tdx_get_cmd(argp, &tdx_cmd); + if (r) + return r; =20 mutex_lock(&kvm->lock); =20 @@ -3171,11 +3180,9 @@ int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __use= r *argp) if (!is_hkid_assigned(kvm_tdx) || kvm_tdx->state =3D=3D TD_STATE_RUNNABLE) return -EINVAL; =20 - if (copy_from_user(&cmd, argp, sizeof(cmd))) - return -EFAULT; - - if (cmd.hw_error) - return -EINVAL; + ret =3D tdx_get_cmd(argp, &cmd); + if (ret) + return ret; =20 switch (cmd.id) { case KVM_TDX_INIT_VCPU: --=20 2.51.1.930.gacf6e81ea2-goog