Description: mm/hugetlb: fix a race between hugetlb sysctl handlers
References:
 https://twitter.com/grsecurity/status/1303749848898904067
Notes:
Bugs:
upstream: released (5.9-rc4) [17743798d81238ab13050e8e2833699b54e15467]
4.19-upstream-stable: released (4.19.144) [221ea9a3da9169dc3c9a364a5f938e215db6419e]
4.9-upstream-stable: released (4.9.236) [47b1be395352d54f888f4331fa291dc9199fff4c]
sid: released (5.8.10-1)
4.19-buster-security: released (4.19.146-1)
4.9-stretch-security: released (4.9.240-1)