提交 3e233385 编写于 作者: B Brijesh Singh 提交者: Paolo Bonzini

KVM: SVM: no need to call access_ok() in LAUNCH_MEASURE command

Using the access_ok() to validate the input before issuing the SEV
command does not buy us anything in this case. If userland is
giving us a garbage pointer then copy_to_user() will catch it when we try
to return the measurement.
Suggested-by: NAl Viro <viro@ZenIV.linux.org.uk>
Fixes: 0d0736f7 (KVM: SVM: Add support for KVM_SEV_LAUNCH_MEASURE ...)
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-kernel@vger.kernel.org
Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: NBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
上级 45d0be87
......@@ -6236,16 +6236,18 @@ static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
{
void __user *measure = (void __user *)(uintptr_t)argp->data;
struct kvm_sev_info *sev = &kvm->arch.sev_info;
struct sev_data_launch_measure *data;
struct kvm_sev_launch_measure params;
void __user *p = NULL;
void *blob = NULL;
int ret;
if (!sev_guest(kvm))
return -ENOTTY;
if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
if (copy_from_user(&params, measure, sizeof(params)))
return -EFAULT;
data = kzalloc(sizeof(*data), GFP_KERNEL);
......@@ -6256,17 +6258,13 @@ static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
if (!params.len)
goto cmd;
if (params.uaddr) {
p = (void __user *)(uintptr_t)params.uaddr;
if (p) {
if (params.len > SEV_FW_BLOB_MAX_SIZE) {
ret = -EINVAL;
goto e_free;
}
if (!access_ok(VERIFY_WRITE, params.uaddr, params.len)) {
ret = -EFAULT;
goto e_free;
}
ret = -ENOMEM;
blob = kmalloc(params.len, GFP_KERNEL);
if (!blob)
......@@ -6290,13 +6288,13 @@ static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
goto e_free_blob;
if (blob) {
if (copy_to_user((void __user *)(uintptr_t)params.uaddr, blob, params.len))
if (copy_to_user(p, blob, params.len))
ret = -EFAULT;
}
done:
params.len = data->len;
if (copy_to_user((void __user *)(uintptr_t)argp->data, &params, sizeof(params)))
if (copy_to_user(measure, &params, sizeof(params)))
ret = -EFAULT;
e_free_blob:
kfree(blob);
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册