| From 03d3e265acc8f83246f87718fb91815a8f5b0bfc Mon Sep 17 00:00:00 2001 |
| From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> |
| Date: Wed, 27 Feb 2019 11:10:17 +0300 |
| Subject: sched/rt: Check integer overflow at usec to nsec conversion |
| |
| [ Upstream commit 1a010e29cfa00fee2888fd2fd4983f848cbafb58 ] |
| |
| Example of unhandled overflows: |
| |
| # echo 18446744073709651 > cpu.rt_runtime_us |
| # cat cpu.rt_runtime_us |
| 99 |
| |
| # echo 18446744073709900 > cpu.rt_period_us |
| # cat cpu.rt_period_us |
| 348 |
| |
| 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/155125501739.293431.5252197504404771496.stgit@buzz |
| Signed-off-by: Ingo Molnar <mingo@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| kernel/sched/rt.c | 5 +++++ |
| 1 file changed, 5 insertions(+) |
| |
| diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c |
| index 90fa23d36565d..1e6b909dca367 100644 |
| --- a/kernel/sched/rt.c |
| +++ b/kernel/sched/rt.c |
| @@ -2555,6 +2555,8 @@ int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
| rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; |
| if (rt_runtime_us < 0) |
| rt_runtime = RUNTIME_INF; |
| + else if ((u64)rt_runtime_us > U64_MAX / NSEC_PER_USEC) |
| + return -EINVAL; |
| |
| return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
| } |
| @@ -2575,6 +2577,9 @@ int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us) |
| { |
| u64 rt_runtime, rt_period; |
| |
| + if (rt_period_us > U64_MAX / NSEC_PER_USEC) |
| + return -EINVAL; |
| + |
| rt_period = rt_period_us * NSEC_PER_USEC; |
| rt_runtime = tg->rt_bandwidth.rt_runtime; |
| |
| -- |
| 2.20.1 |
| |
