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    Subject[tip:tracing/urgent] tracing: fix a typo in tracing_cpumask_write()
    Commit-ID:  215368e8e59023d6a0abdda896923018d74fdf7f
    Gitweb: http://git.kernel.org/tip/215368e8e59023d6a0abdda896923018d74fdf7f
    Author: Li Zefan <lizf@cn.fujitsu.com>
    AuthorDate: Mon, 15 Jun 2009 10:56:42 +0800
    Committer: Steven Rostedt <rostedt@goodmis.org>
    CommitDate: Mon, 15 Jun 2009 11:37:12 -0400

    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>


    ---
    kernel/trace/trace.c | 6 +++---
    1 files changed, 3 insertions(+), 3 deletions(-)

    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 @@ 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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