Commit 0f41fcf7 authored May 15, 2019 by Helen Koike Committed by Mike Snitzer May 16, 2019

dm ioctl: fix hang in early create error condition



The dm_early_create() function (which deals with "dm-mod.create=" kernel
command line option) calls dm_hash_insert() who gets an extra reference
to the md object.

In case of failure, this reference wasn't being released, causing
dm_destroy() to hang, thus hanging the whole boot process.

Fix this by calling __hash_remove() in the error path.

Fixes: 6bbc923d ("dm: add support to directly boot to a mapped device")
Cc: stable@vger.kernel.org
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

parent 05d6909e

drivers/md/dm-ioctl.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -2069,7 +2069,7 @@ int __init dm_early_create(struct dm_ioctl *dmi,
		/* alloc table */
		r = dm_table_create(&t, get_mode(dmi), dmi->target_count, md);
		if (r)
		goto err_destroy_dm;
		goto err_hash_remove;

		/* add targets */
		for (i = 0; i < dmi->target_count; i++) {
		@@ -2116,6 +2116,10 @@ int __init dm_early_create(struct dm_ioctl *dmi,

		err_destroy_table:
		dm_table_destroy(t);
		err_hash_remove:
		(void) __hash_remove(__get_name_cell(dmi->name));
		/* release reference from __get_name_cell */
		dm_put(md);
		err_destroy_dm:
		dm_put(md);
		dm_destroy(md);

Admin message