1 files changed, 77 insertions, 11 deletions

diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 06d3d3c44bf7..81346aeebb39 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -406,6 +406,30 @@ get_var_data(struct efivars *efivars, struct efi_variable *var)
 	return status;
 }
 
+static efi_status_t
+check_var_size_locked(struct efivars *efivars, u32 attributes,
+			unsigned long size)
+{
+	u64 storage_size, remaining_size, max_size;
+	efi_status_t status;
+	const struct efivar_operations *fops = efivars->ops;
+
+	if (!efivars->ops->query_variable_info)
+		return EFI_UNSUPPORTED;
+
+	status = fops->query_variable_info(attributes, &storage_size,
+					   &remaining_size, &max_size);
+
+	if (status != EFI_SUCCESS)
+		return status;
+
+	if (!storage_size || size > remaining_size || size > max_size ||
+	    (remaining_size - size) < (storage_size / 2))
+		return EFI_OUT_OF_RESOURCES;
+
+	return status;
+}
+
 static ssize_t
 efivar_guid_read(struct efivar_entry *entry, char *buf)
 {
@@ -527,11 +551,16 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
 	}
 
 	spin_lock_irq(&efivars->lock);
-	status = efivars->ops->set_variable(new_var->VariableName,
-					    &new_var->VendorGuid,
-					    new_var->Attributes,
-					    new_var->DataSize,
-					    new_var->Data);
+
+	status = check_var_size_locked(efivars, new_var->Attributes,
+	       new_var->DataSize + utf16_strsize(new_var->VariableName, 1024));
+
+	if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
+		status = efivars->ops->set_variable(new_var->VariableName,
+						    &new_var->VendorGuid,
+						    new_var->Attributes,
+						    new_var->DataSize,
+						    new_var->Data);
 
 	spin_unlock_irq(&efivars->lock);
 
@@ -638,6 +667,36 @@ efivar_unregister(struct efivar_entry *var)
 	kobject_put(&var->kobj);
 }
 
+static int efi_status_to_err(efi_status_t status)
+{
+	int err;
+
+	switch (status) {
+	case EFI_INVALID_PARAMETER:
+		err = -EINVAL;
+		break;
+	case EFI_OUT_OF_RESOURCES:
+		err = -ENOSPC;
+		break;
+	case EFI_DEVICE_ERROR:
+		err = -EIO;
+		break;
+	case EFI_WRITE_PROTECTED:
+		err = -EROFS;
+		break;
+	case EFI_SECURITY_VIOLATION:
+		err = -EACCES;
+		break;
+	case EFI_NOT_FOUND:
+		err = -ENOENT;
+		break;
+	default:
+		err = -EINVAL;
+	}
+
+	return err;
+}
+
 #ifdef CONFIG_PSTORE
 
 static int efi_pstore_open(struct pstore_info *psi)
@@ -707,7 +766,6 @@ static int efi_pstore_write(enum pstore_type_id type, u64 *id,
 	struct efivars *efivars = psi->data;
 	struct efivar_entry *entry, *found = NULL;
 	int i, ret = 0;
-	u64 storage_space, remaining_space, max_variable_size;
 	efi_status_t status = EFI_NOT_FOUND;
 	unsigned long flags;
 
@@ -721,11 +779,11 @@ static int efi_pstore_write(enum pstore_type_id type, u64 *id,
 	 * size: a size of logging data
 	 * DUMP_NAME_LEN * 2: a maximum size of variable name
 	 */
-	status = efivars->ops->query_variable_info(PSTORE_EFI_ATTRIBUTES,
-						   &storage_space,
-						   &remaining_space,
-						   &max_variable_size);
-	if (status || remaining_space < size + DUMP_NAME_LEN * 2) {
+
+	status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES,
+					 size + DUMP_NAME_LEN * 2);
+
+	if (status) {
 		spin_unlock_irqrestore(&efivars->lock, flags);
 		*id = part;
 		return -ENOSPC;
@@ -872,6 +930,14 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
 		return -EINVAL;
 	}
 
+	status = check_var_size_locked(efivars, new_var->Attributes,
+	       new_var->DataSize + utf16_strsize(new_var->VariableName, 1024));
+
+	if (status && status != EFI_UNSUPPORTED) {
+		spin_unlock_irq(&efivars->lock);
+		return efi_status_to_err(status);
+	}
+
 	/* now *really* create the variable via EFI */
 	status = efivars->ops->set_variable(new_var->VariableName,
 					    &new_var->VendorGuid,