dmaengine: idxd: fix memory leak in error handling path of idxd_setup_wqs

Memory allocated for wqs is not freed if an error occurs during
idxd_setup_wqs(). To fix it, free the allocated memory in the reverse
order of allocation before exiting the function in case of an error.

Fixes: 7c5dd23 ("dmaengine: idxd: fix wq conf_dev 'struct device' lifetime")
Fixes: 700af3a ("dmaengine: idxd: add 'struct idxd_dev' as wrapper for conf_dev")
Fixes: de5819b ("dmaengine: idxd: track enabled workqueues in bitmap")
Fixes: b0325ae ("dmaengine: idxd: add WQ operation cap restriction support")
Cc: stable@vger.kernel.org
Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Link: https://lore.kernel.org/r/20250404120217.48772-2-xueshuai@linux.alibaba.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: axiqia

drivers/dma/idxd/init.c

@@ -169,8 +169,8 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
 
 	idxd->wq_enable_map = bitmap_zalloc_node(idxd->max_wqs, GFP_KERNEL, dev_to_node(dev));
 	if (!idxd->wq_enable_map) {
-		kfree(idxd->wqs);
-		return -ENOMEM;
+		rc = -ENOMEM;
+		goto err_bitmap;
 	}
 
 	for (i = 0; i < idxd->max_wqs; i++) {
@@ -189,10 +189,8 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
 		conf_dev->bus = &dsa_bus_type;
 		conf_dev->type = &idxd_wq_device_type;
 		rc = dev_set_name(conf_dev, "wq%d.%d", idxd->id, wq->id);
-		if (rc < 0) {
-			put_device(conf_dev);
+		if (rc < 0)
 			goto err;
-		}
 
 		mutex_init(&wq->wq_lock);
 		init_waitqueue_head(&wq->err_queue);
@@ -203,17 +201,15 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
 		wq->enqcmds_retries = IDXD_ENQCMDS_RETRIES;
 		wq->wqcfg = kzalloc_node(idxd->wqcfg_size, GFP_KERNEL, dev_to_node(dev));
 		if (!wq->wqcfg) {
-			put_device(conf_dev);
 			rc = -ENOMEM;
 			goto err;
 		}
 
 		if (idxd->hw.wq_cap.op_config) {
 			wq->opcap_bmap = bitmap_zalloc(IDXD_MAX_OPCAP_BITS, GFP_KERNEL);
 			if (!wq->opcap_bmap) {
-				put_device(conf_dev);
 				rc = -ENOMEM;
-				goto err;
+				goto err_opcap_bmap;
 			}
 			bitmap_copy(wq->opcap_bmap, idxd->opcap_bmap, IDXD_MAX_OPCAP_BITS);
 		}
@@ -224,12 +220,28 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
 
 	return 0;
 
- err:
+err_opcap_bmap:
+	kfree(wq->wqcfg);
+
+err:
+	put_device(conf_dev);
+	kfree(wq);
+
 	while (--i >= 0) {
 		wq = idxd->wqs[i];
+		if (idxd->hw.wq_cap.op_config)
+			bitmap_free(wq->opcap_bmap);
+		kfree(wq->wqcfg);
 		conf_dev = wq_confdev(wq);
 		put_device(conf_dev);
+		kfree(wq);
+
 	}
+	bitmap_free(idxd->wq_enable_map);
+
+err_bitmap:
+	kfree(idxd->wqs);
+
 	return rc;
 }