accel/qaic: Validate user data before grabbing any lock

Validating user data does not need to be protected by any lock and it is
safe to move it out of critical region.

Fixes: ff13be8 ("accel/qaic: Add datapath")
Fixes: 129776a ("accel/qaic: Add control path")
Signed-off-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
Reviewed-by: Carl Vanderlip <quic_carlv@quicinc.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230517193540.14323-2-quic_jhugo@quicinc.com

Author: Pranjal Ramajor Asha Kanojiya

drivers/accel/qaic/qaic_control.c

@@ -1249,7 +1249,7 @@ static int qaic_manage(struct qaic_device *qdev, struct qaic_user *usr, struct m
 
 int qaic_manage_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
 {
-	struct qaic_manage_msg *user_msg;
+	struct qaic_manage_msg *user_msg = data;
 	struct qaic_device *qdev;
 	struct manage_msg *msg;
 	struct qaic_user *usr;
@@ -1258,6 +1258,9 @@ int qaic_manage_ioctl(struct drm_device *dev, void *data, struct drm_file *file_
 	int usr_rcu_id;
 	int ret;
 
+	if (user_msg->len > QAIC_MANAGE_MAX_MSG_LENGTH)
+		return -EINVAL;
+
 	usr = file_priv->driver_priv;
 
 	usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
@@ -1275,13 +1278,6 @@ int qaic_manage_ioctl(struct drm_device *dev, void *data, struct drm_file *file_
 		return -ENODEV;
 	}
 
-	user_msg = data;
-
-	if (user_msg->len > QAIC_MANAGE_MAX_MSG_LENGTH) {
-		ret = -EINVAL;
-		goto out;
-	}
-
 	msg = kzalloc(QAIC_MANAGE_MAX_MSG_LENGTH + sizeof(*msg), GFP_KERNEL);
 	if (!msg) {
 		ret = -ENOMEM;

drivers/accel/qaic/qaic_data.c

@@ -663,6 +663,10 @@ int qaic_create_bo_ioctl(struct drm_device *dev, void *data, struct drm_file *fi
 	if (args->pad)
 		return -EINVAL;
 
+	size = PAGE_ALIGN(args->size);
+	if (size == 0)
+		return -EINVAL;
+
 	usr = file_priv->driver_priv;
 	usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
 	if (!usr->qddev) {
@@ -677,12 +681,6 @@ int qaic_create_bo_ioctl(struct drm_device *dev, void *data, struct drm_file *fi
 		goto unlock_dev_srcu;
 	}
 
-	size = PAGE_ALIGN(args->size);
-	if (size == 0) {
-		ret = -EINVAL;
-		goto unlock_dev_srcu;
-	}
-
 	bo = qaic_alloc_init_bo();
 	if (IS_ERR(bo)) {
 		ret = PTR_ERR(bo);
@@ -936,6 +934,22 @@ int qaic_attach_slice_bo_ioctl(struct drm_device *dev, void *data, struct drm_fi
 	struct qaic_bo *bo;
 	int ret;
 
+	if (args->hdr.count == 0)
+		return -EINVAL;
+
+	arg_size = args->hdr.count * sizeof(*slice_ent);
+	if (arg_size / args->hdr.count != sizeof(*slice_ent))
+		return -EINVAL;
+
+	if (args->hdr.size == 0)
+		return -EINVAL;
+
+	if (!(args->hdr.dir == DMA_TO_DEVICE || args->hdr.dir == DMA_FROM_DEVICE))
+		return -EINVAL;
+
+	if (args->data == 0)
+		return -EINVAL;
+
 	usr = file_priv->driver_priv;
 	usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
 	if (!usr->qddev) {
@@ -950,43 +964,17 @@ int qaic_attach_slice_bo_ioctl(struct drm_device *dev, void *data, struct drm_fi
 		goto unlock_dev_srcu;
 	}
 
-	if (args->hdr.count == 0) {
-		ret = -EINVAL;
-		goto unlock_dev_srcu;
-	}
-
-	arg_size = args->hdr.count * sizeof(*slice_ent);
-	if (arg_size / args->hdr.count != sizeof(*slice_ent)) {
-		ret = -EINVAL;
-		goto unlock_dev_srcu;
-	}
-
 	if (args->hdr.dbc_id >= qdev->num_dbc) {
 		ret = -EINVAL;
 		goto unlock_dev_srcu;
 	}
 
-	if (args->hdr.size == 0) {
-		ret = -EINVAL;
-		goto unlock_dev_srcu;
-	}
-
-	if (!(args->hdr.dir == DMA_TO_DEVICE  || args->hdr.dir == DMA_FROM_DEVICE)) {
-		ret = -EINVAL;
-		goto unlock_dev_srcu;
-	}
-
 	dbc = &qdev->dbc[args->hdr.dbc_id];
 	if (dbc->usr != usr) {
 		ret = -EINVAL;
 		goto unlock_dev_srcu;
 	}
 
-	if (args->data == 0) {
-		ret = -EINVAL;
-		goto unlock_dev_srcu;
-	}
-
 	user_data = u64_to_user_ptr(args->data);
 
 	slice_ent = kzalloc(arg_size, GFP_KERNEL);
@@ -1316,7 +1304,6 @@ static int __qaic_execute_bo_ioctl(struct drm_device *dev, void *data, struct dr
 	received_ts = ktime_get_ns();
 
 	size = is_partial ? sizeof(*pexec) : sizeof(*exec);
-
 	n = (unsigned long)size * args->hdr.count;
 	if (args->hdr.count == 0 || n / args->hdr.count != size)
 		return -EINVAL;
@@ -1665,6 +1652,9 @@ int qaic_wait_bo_ioctl(struct drm_device *dev, void *data, struct drm_file *file
 	int rcu_id;
 	int ret;
 
+	if (args->pad != 0)
+		return -EINVAL;
+
 	usr = file_priv->driver_priv;
 	usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
 	if (!usr->qddev) {
@@ -1679,11 +1669,6 @@ int qaic_wait_bo_ioctl(struct drm_device *dev, void *data, struct drm_file *file
 		goto unlock_dev_srcu;
 	}
 
-	if (args->pad != 0) {
-		ret = -EINVAL;
-		goto unlock_dev_srcu;
-	}
-
 	if (args->dbc_id >= qdev->num_dbc) {
 		ret = -EINVAL;
 		goto unlock_dev_srcu;