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Groups > linux.kernel > #1592961

[PATCH -stable 4.1 4/4] perf/core: Fix the perf_cpu_time_max_percent check

From Tan Xiaojun <tanxiaojun@huawei.com>
Newsgroups linux.kernel
Subject [PATCH -stable 4.1 4/4] perf/core: Fix the perf_cpu_time_max_percent check
Date 2017-03-06 08:10 +0100
Message-ID <thUWm-4mz-9@gated-at.bofh.it> (permalink)
References <thUMG-43s-7@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Use "proc_dointvec_minmax" instead of "proc_dointvec" to check the input
value from user-space.

If not, we can set a big value and some vars will overflow like
"sysctl_perf_event_sample_rate" which will cause a lot of unexpected
problems.

Signed-off-by: Tan Xiaojun <tanxiaojun@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <acme@kernel.org>
Cc: <alexander.shishkin@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1487829879-56237-1-git-send-email-tanxiaojun@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/events/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 350c45a..5b50b06 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -236,7 +236,7 @@ int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
 				void __user *buffer, size_t *lenp,
 				loff_t *ppos)
 {
-	int ret = proc_dointvec(table, write, buffer, lenp, ppos);
+	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 
 	if (ret || !write)
 		return ret;
-- 
1.9.1

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[PATCH -stable 4.1 4/4] perf/core: Fix the perf_cpu_time_max_percent check Tan Xiaojun <tanxiaojun@huawei.com> - 2017-03-06 08:10 +0100

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