4.4-stable review patch. If anyone has any objections, please let me know.
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From: Tan Xiaojun tanxiaojun@huawei.com
commit 1572e45a924f254d9570093abde46430c3172e3d upstream.
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... Signed-off-by: Ingo Molnar mingo@kernel.org Cc: Guenter Roeck linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -229,7 +229,7 @@ int perf_cpu_time_max_percent_handler(st 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;