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

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

Fixes: 75b9113 ("dmaengine: idxd: fix engine conf_dev lifetime")
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/20250404120217.48772-3-xueshuai@linux.alibaba.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: axiqia

drivers/dma/idxd/init.c

@@ -275,6 +275,7 @@ static int idxd_setup_engines(struct idxd_device *idxd)
 		rc = dev_set_name(conf_dev, "engine%d.%d", idxd->id, engine->id);
 		if (rc < 0) {
 			put_device(conf_dev);
+			kfree(engine);
 			goto err;
 		}
 
@@ -288,7 +289,10 @@ static int idxd_setup_engines(struct idxd_device *idxd)
 		engine = idxd->engines[i];
 		conf_dev = engine_confdev(engine);
 		put_device(conf_dev);
+		kfree(engine);
 	}
+	kfree(idxd->engines);
+
 	return rc;
 }