Commit fe9d31fd authored by Ma Ke's avatar Ma Ke Committed by Andrew Morton
Browse files

mm/hmm/test: fix error handling in dmirror_device_init 

dmirror_device_init() calls device_initialize() which sets the device
reference count to 1, but fails to call put_device() when error occurs
after dev_set_name() or cdev_device_add() failures.  This results in
memory leaks of struct device objects.  Additionally,
dmirror_device_remove() lacks the final put_device() call to properly
release the device reference.

Found by code review.

Link: https://lkml.kernel.org/r/20251108115346.6368-1-make24@iscas.ac.cn


Fixes: 6a760f58 ("mm/hmm/test: use char dev with struct device to get device node")
Signed-off-by: default avatarMa Ke <make24@iscas.ac.cn>
Cc: Haoxiang Li <make24@iscas.ac.cn>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Mika Penttilä <mpenttil@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 50d0598c

lib/test_hmm.c

+7 −2
Original line number Diff line number Diff line
@@ -1740,20 +1740,25 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id) 


	ret = dev_set_name(&mdevice->device, "hmm_dmirror%u", id);

	if (ret)

		return ret;

		goto put_device;



	ret = cdev_device_add(&mdevice->cdevice, &mdevice->device);

	if (ret)

		return ret;

		goto put_device;



	/* Build a list of free ZONE_DEVICE struct pages */

	return dmirror_allocate_chunk(mdevice, NULL, false);



put_device:

	put_device(&mdevice->device);

	return ret;

}



static void dmirror_device_remove(struct dmirror_device *mdevice)

{

	dmirror_device_remove_chunks(mdevice);

	cdev_device_del(&mdevice->cdevice, &mdevice->device);

	put_device(&mdevice->device);

}



static int __init hmm_dmirror_init(void)