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>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8acd9b8..7355a38 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2191,11 +2191,12 @@
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 @@
return count;
err_unlock:
- mutex_unlock(&tracing_cpumask_update_lock);
- free_cpumask_var(tracing_cpumask);
+ free_cpumask_var(tracing_cpumask_new);
return err;
}