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: 6bbc923dfcf57d ("dm: add support to directly boot to a mapped device") Cc: stable@vger.kernel.org Signed-off-by: Helen Koike helen.koike@collabora.com

--- Hi,

I also tested this patch version with the new test case in the following test script:

https://gitlab.collabora.com/koike/dm-cmdline-test/commit/d2d7a0ee4a49931cdb...

Thanks Helen

Changes in v2: - instead of modifying dm_hash_insert() to return the hash cell, use __get_name_cell(dmi->name) instead.

drivers/md/dm-ioctl.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index c740153b4e52..1e03bc89e20f 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -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);