Messages in this thread Patch in this message | | | Subject | [PATCH 3/3] sched/core: check quota and period overflow at usec to nsec conversion | From | Konstantin Khlebnikov <> | Date | Wed, 27 Feb 2019 11:10:20 +0300 |
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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> --- 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 a626fbd9fdc7..5f46aa335b28 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6606,8 +6606,10 @@ 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); } @@ -6629,6 +6631,9 @@ 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;
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