Commit-ID: 1a8b4540db732ca16c9e43ac7c08b1b8f0b252d8 Gitweb: https://git.kernel.org/tip/1a8b4540db732ca16c9e43ac7c08b1b8f0b252d8 Author: Konstantin Khlebnikov <khlebni...@yandex-team.ru> AuthorDate: Wed, 27 Feb 2019 11:10:20 +0300 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 19 Apr 2019 13:42:10 +0200
sched/core: Check quota and period overflow at usec to nsec conversion 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 <khlebni...@yandex-team.ru> Acked-by: Peter Zijlstra <a.p.zijls...@chello.nl> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/155125502079.293431.3947497929372138600.stgit@buzz Signed-off-by: Ingo Molnar <mi...@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 685b1541ce51..de8ab411826c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6611,8 +6611,10 @@ static 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); } @@ -6634,6 +6636,9 @@ static 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;
