Commit 215368e8 authored Jun 15, 2009 by Li Zefan Committed by Steven Rostedt Jun 15, 2009

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: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A35B86A.7070608@cn.fujitsu.com>
Signed-off-by: Steven 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;
		}

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