diff options
| -rw-r--r-- | mm/memcontrol.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0b38b6ad547d..5de0a9035b5f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6360,11 +6360,16 @@ static unsigned long effective_protection(unsigned long usage, * We're using unprotected memory for the weight so that if * some cgroups DO claim explicit protection, we don't protect * the same bytes twice. + * + * Check both usage and parent_usage against the respective + * protected values. One should imply the other, but they + * aren't read atomically - make sure the division is sane. */ if (!(cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT)) return ep; - - if (parent_effective > siblings_protected && usage > protected) { + if (parent_effective > siblings_protected && + parent_usage > siblings_protected && + usage > protected) { unsigned long unclaimed; unclaimed = parent_effective - siblings_protected; |