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: needed
4.9-upstream-stable: needed
sid: pending (5.8.9-1)
4.19-buster-security: needed
4.9-stretch-security: needed