mainline inclusion
from mainline-5.1
commit a734d1f4c2fc
category: bugfix
bugzilla: 15155
CVE: NA

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

nla_nest_start may fail and thus deserves a check.
The fix returns -EMSGSIZE when it fails.
Signed-off-by: NKangjie Lu <kjlu@umn.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NZhiqiang Liu <liuzhiqiang26@huawei.com>
Reviewed-by: NWenan Mao <maowenan@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>