Commit-ID:  1572e45a924f254d9570093abde46430c3172e3d
Gitweb:     http://git.kernel.org/tip/1572e45a924f254d9570093abde46430c3172e3d
Author:     Tan Xiaojun <tanxiao...@huawei.com>
AuthorDate: Thu, 23 Feb 2017 14:04:39 +0800
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Fri, 24 Feb 2017 08:56:33 +0100

perf/core: Fix the perf_cpu_time_max_percent check

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 <tanxiao...@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Cc: <a...@kernel.org>
Cc: <alexander.shish...@linux.intel.com>
Cc: Alexander Shishkin <alexander.shish...@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Stephane Eranian <eran...@google.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Vince Weaver <vincent.wea...@maine.edu>
Link: 
http://lkml.kernel.org/r/1487829879-56237-1-git-send-email-tanxiao...@huawei.com
Signed-off-by: Ingo Molnar <mi...@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 d4e3f8d..c1c1cdf 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -455,7 +455,7 @@ 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;

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