| From b66d90b50b2fb988e3a4a9cceced6120b954cbb1 Mon Sep 17 00:00:00 2001 |
| From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> |
| Date: Wed, 27 Feb 2019 11:10:20 +0300 |
| Subject: sched/core: Check quota and period overflow at usec to nsec |
| conversion |
| |
| [ 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 4778c48a7fda4..89c9c1d7d22c5 100644 |
| --- a/kernel/sched/core.c |
| +++ b/kernel/sched/core.c |
| @@ -6661,8 +6661,10 @@ 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); |
| } |
| @@ -6684,6 +6686,9 @@ 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; |
| |
| -- |
| 2.20.1 |
| |