From: Peter Zijlstra <peterz@infradead.org>
To: linux-kernel@vger.kernel.org, mingo@kernel.org
Cc: tglx@linutronix.de, dan.j.williams@intel.com,
torvalds@linux-foundation.org,
Dan Carpenter <dan.carpenter@oracle.com>,
"Peter Zijlstra" <peterz@infradead.org>
Subject: [PATCH 6/7] sched: Fix possible Spectre-v1 for sched_prio_to_weight[]
Date: Fri, 20 Apr 2018 15:14:13 +0200 [thread overview]
Message-ID: <20180420131631.977597863@infradead.org> (raw)
In-Reply-To: 20180420131407.721875616@infradead.org
[-- Attachment #1: peterz-spectre1-6.patch --]
[-- Type: text/plain, Size: 897 bytes --]
> kernel/sched/core.c:6921 cpu_weight_nice_write_s64() warn: potential spectre issue 'sched_prio_to_weight'
Userspace controls @nice, so sanitize the value before using it to
index an array.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
---
kernel/sched/core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6928,11 +6928,14 @@ static int cpu_weight_nice_write_s64(str
struct cftype *cft, s64 nice)
{
unsigned long weight;
+ int idx;
if (nice < MIN_NICE || nice > MAX_NICE)
return -ERANGE;
- weight = sched_prio_to_weight[NICE_TO_PRIO(nice) - MAX_RT_PRIO];
+ idx = array_index_nospec(NICE_TO_PRIO(nice) - MAX_RT_PRIO, 40);
+ weight = sched_prio_to_weight[idx];
+
return sched_group_set_shares(css_tg(css), scale_load(weight));
}
#endif
next prev parent reply other threads:[~2018-04-20 13:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-20 13:14 [PATCH 0/7] Various Spectre-v1 fixes Peter Zijlstra
2018-04-20 13:14 ` [PATCH 1/7] perf: Fix possible Spectre-v1 for aux_pages Peter Zijlstra
2018-04-20 13:14 ` [PATCH 2/7] perf,x86: Fix possible Spectre-v1 for hw_perf_event Peter Zijlstra
2018-04-20 13:14 ` [PATCH 3/7] perf,x86: Fix possible Spectre-v1 for x86_pmu::event_map() Peter Zijlstra
2018-04-20 13:14 ` [PATCH 4/7] perf,x86/msr: Fix possible Spectre-v1 for msr Peter Zijlstra
2018-04-20 13:14 ` [PATCH 5/7] perf,x86/cstate: Fix possible Spectre-v1 for pkg_msr Peter Zijlstra
2018-04-20 13:14 ` Peter Zijlstra [this message]
2018-04-20 13:14 ` [PATCH 7/7] sched,autogroup: Fix possible Spectre-v1 for sched_prio_to_weight Peter Zijlstra
2018-04-23 1:03 ` [PATCH 0/7] Various Spectre-v1 fixes Michal Hocko
2018-04-23 9:33 ` Peter Zijlstra
2018-04-23 13:50 ` Dan Williams
2018-04-23 16:47 ` Michal Hocko
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