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From: tip-bot for Konstantin Khlebnikov <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: hpa@zytor.com, a.p.zijlstra@chello.nl, peterz@infradead.org,
	tglx@linutronix.de, linux-kernel@vger.kernel.org,
	mingo@kernel.org, torvalds@linux-foundation.org,
	khlebnikov@yandex-team.ru
Subject: [tip:sched/core] sched/core: Check quota and period overflow at usec to nsec conversion
Date: Fri, 19 Apr 2019 05:17:45 -0700	[thread overview]
Message-ID: <tip-1a8b4540db732ca16c9e43ac7c08b1b8f0b252d8@git.kernel.org> (raw)
In-Reply-To: <155125502079.293431.3947497929372138600.stgit@buzz>

Commit-ID:  1a8b4540db732ca16c9e43ac7c08b1b8f0b252d8
Gitweb:     https://git.kernel.org/tip/1a8b4540db732ca16c9e43ac7c08b1b8f0b252d8
Author:     Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
AuthorDate: Wed, 27 Feb 2019 11:10:20 +0300
Committer:  Ingo Molnar <mingo@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 <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>
---
 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;
 

  reply	other threads:[~2019-04-19 19:04 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-27  8:10 [PATCH 1/3] sched/rt: check integer overflow at usec to nsec conversion Konstantin Khlebnikov
2019-02-27  8:10 ` [PATCH 2/3] sched/core: handle overflow in cpu_shares_write_u64 Konstantin Khlebnikov
2019-04-19 12:16   ` [tip:sched/core] sched/core: Handle " tip-bot for Konstantin Khlebnikov
2019-02-27  8:10 ` [PATCH 3/3] sched/core: check quota and period overflow at usec to nsec conversion Konstantin Khlebnikov
2019-04-19 12:17   ` tip-bot for Konstantin Khlebnikov [this message]
2019-04-19 12:16 ` [tip:sched/core] sched/rt: Check integer " tip-bot for Konstantin Khlebnikov

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