[ Upstream commit 1a8b4540db732ca16c9e43ac7c08b1b8f0b252d8 ]
Large values could overflow u64 and pass following sanity checks.
# echo 18446744073750000 > cpu.cfs_period_us # cat cpu.cfs_period_us 40448
# echo 18446744073750000 > cpu.cfs_quota_us # cat cpu.cfs_quota_us 40448
After this patch they will fail with -EINVAL.
Signed-off-by: Konstantin Khlebnikov khlebnikov@yandex-team.ru Acked-by: Peter Zijlstra a.p.zijlstra@chello.nl Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/155125502079.293431.3947497929372138600.stgit@buzz Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/sched/core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0552ddbb25e2a..2464a242d6c9d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6482,8 +6482,10 @@ int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) period = ktime_to_ns(tg->cfs_bandwidth.period); if (cfs_quota_us < 0) quota = RUNTIME_INF; - else + else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC) quota = (u64)cfs_quota_us * NSEC_PER_USEC; + else + return -EINVAL;
return tg_set_cfs_bandwidth(tg, period, quota); } @@ -6505,6 +6507,9 @@ int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) { u64 quota, period;
+ if ((u64)cfs_period_us > U64_MAX / NSEC_PER_USEC) + return -EINVAL; + period = (u64)cfs_period_us * NSEC_PER_USEC; quota = tg->cfs_bandwidth.quota;