Commit 1a0db774 authored by Zenghui Yu's avatar Zenghui Yu Committed by Martin K. Petersen
Browse files

scsi: bsg: Fix device unregistration 

device_initialize() is used to take a refcount on the device. However,
put_device() is not called during device teardown. This leads to a
leak of private data of the driver core, dev_name(), etc. This is
reported by kmemleak at boot time if we compile kernel with
DEBUG_TEST_DRIVER_REMOVE.

Fix memory leaks during unregistration and implement a release
function.

Link: https://lore.kernel.org/r/20210911105306.1511-1-yuzenghui@huawei.com


Fixes: ead09dd3 ("scsi: bsg: Simplify device registration")
Reviewed-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 4521428c

block/bsg.c

+15 −8
Original line number Diff line number Diff line
@@ -165,13 +165,20 @@ static const struct file_operations bsg_fops = { 
	.llseek		=	default_llseek,

};



static void bsg_device_release(struct device *dev)

{

	struct bsg_device *bd = container_of(dev, struct bsg_device, device);



	ida_simple_remove(&bsg_minor_ida, MINOR(bd->device.devt));

	kfree(bd);

}



void bsg_unregister_queue(struct bsg_device *bd)

{

	if (bd->queue->kobj.sd)

		sysfs_remove_link(&bd->queue->kobj, "bsg");

	cdev_device_del(&bd->cdev, &bd->device);

	ida_simple_remove(&bsg_minor_ida, MINOR(bd->device.devt));

	kfree(bd);

	put_device(&bd->device);

}

EXPORT_SYMBOL_GPL(bsg_unregister_queue);
@@ -193,11 +200,13 @@ struct bsg_device *bsg_register_queue(struct request_queue *q, 
	if (ret < 0) {

		if (ret == -ENOSPC)

			dev_err(parent, "bsg: too many bsg devices\n");

		goto out_kfree;

		kfree(bd);

		return ERR_PTR(ret);

	}

	bd->device.devt = MKDEV(bsg_major, ret);

	bd->device.class = bsg_class;

	bd->device.parent = parent;

	bd->device.release = bsg_device_release;

	dev_set_name(&bd->device, "%s", name);

	device_initialize(&bd->device);
@@ -205,7 +214,7 @@ struct bsg_device *bsg_register_queue(struct request_queue *q, 
	bd->cdev.owner = THIS_MODULE;

	ret = cdev_device_add(&bd->cdev, &bd->device);

	if (ret)

		goto out_ida_remove;

		goto out_put_device;



	if (q->kobj.sd) {

		ret = sysfs_create_link(&q->kobj, &bd->device.kobj, "bsg");
@@ -217,10 +226,8 @@ struct bsg_device *bsg_register_queue(struct request_queue *q, 


out_device_del:

	cdev_device_del(&bd->cdev, &bd->device);

out_ida_remove:

	ida_simple_remove(&bsg_minor_ida, MINOR(bd->device.devt));

out_kfree:

	kfree(bd);

out_put_device:

	put_device(&bd->device);

	return ERR_PTR(ret);

}

EXPORT_SYMBOL_GPL(bsg_register_queue);