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Commit 215368e8 authored by Li Zefan's avatar Li Zefan Committed by Steven Rostedt
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tracing: fix a typo in tracing_cpumask_write() 



It's tracing_cpumask_new that should be kfree()ed.

This causes tracing_cpumask to be freed due to the typo:

 # echo z > tracing_cpumask
 bash: echo: write error: Invalid argument

And subsequent reads/writes to tracing_cpuamsk will access this
already-freed tracing_cpumask, thus may lead to crash.

[ Impact: fix leak and crash when writing invalid val to tracing_cpumask ]

Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A35B86A.7070608@cn.fujitsu.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 78be6914

kernel/trace/trace.c

+3 −3
Original line number Diff line number Diff line
@@ -2191,11 +2191,12 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, 
	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))

		return -ENOMEM;



	mutex_lock(&tracing_cpumask_update_lock);

	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);

	if (err)

		goto err_unlock;



	mutex_lock(&tracing_cpumask_update_lock);



	local_irq_disable();

	__raw_spin_lock(&ftrace_max_lock);

	for_each_tracing_cpu(cpu) {
@@ -2223,8 +2224,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, 
	return count;



err_unlock:

	mutex_unlock(&tracing_cpumask_update_lock);

	free_cpumask_var(tracing_cpumask);

	free_cpumask_var(tracing_cpumask_new);



	return err;

}