net: ieee802154: fix null deref in parse dev addr

stable inclusion
from stable-v4.19.196
commit 5f728ec65485625e30f46e5b4917ff023ad29ea0
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4JK
CVE: CVE-2021-47257

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5f728ec65485625e30f46e5b4917ff023ad29ea0



--------------------------------

[ Upstream commit 9fdd0491 ]

Fix a logic error that could result in a null deref if the user sets
the mode incorrectly for the given addr type.

Signed-off-by: Dan Robertson <dan@dlrobertson.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210423040214.15438-2-dan@dlrobertson.com


Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Liu Mingrui <liumingrui@huawei.com>