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    SubjectRe: [PATCH 6/6] mqueue: fix mq_open() file descriptor leak on user-space processes
    From
    On Thu, Feb 25, 2010 at 2:59 PM, Américo Wang <xiyou.wangcong@gmail.com> wrote:
    > On Thu, Feb 25, 2010 at 12:25 PM, Américo Wang <xiyou.wangcong@gmail.com> wrote:
    >> On Thu, Feb 25, 2010 at 12:00 PM, Xiaotian Feng <xtfeng@gmail.com> wrote:
    >>> 2010/2/25 Américo Wang <xiyou.wangcong@gmail.com>:
    >>>> On Tue, Feb 23, 2010 at 3:04 PM, André Goddard Rosa
    >>>> <andre.goddard@gmail.com> wrote:
    >>>>> It can be triggered by the following test program:
    >>>>>
    >>>>
    >>>> <snip>
    >>>>
    >>>>>
    >>>>> When not running valgrind, user-space program segfaults trying to execute
    >>>>> strerror(errno). With valgrind, it executes successfully and prints the
    >>>>> 5 open files: stdin, stdout, stderr, pipe[0] and pipe[1].
    >>>>>
    >>>>> Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
    >>>>> ---
    >>>>
    >>>> The code has more than just this problem, could you please try
    >>>> my patch below?
    >>>>
    >>>> Thanks.
    >>>>
    >>>> ---------------------------->
    >>>>
    >>>> Clean up the failure path of sys_mq_open().
    >>>>
    >>>> Reorder the goto labels;
    >>>> Rename 'upsem' to 'upunlock';
    >>>> Remove some unused labels;
    >>>> Fix some wrong goto path.
    >>>>
    >>>
    >>> I think it's wrong to move dput after mntput
    >>
    >> Oh, this is to say mntget() should be called before lookup_one_len(),
    >> the original code seems wrong again...
    >>
    >
    > How about the one below?

    This is definitely wrong,

    if (IS_ERR(filp)) {
    error = PTR_ERR(filp);
    - goto out_putfd;
    + goto out;
    }

    filp is assigned by do_open or do_create in mqueue.c, take a look at
    the code, if do_open/do_create is failed, kernel is already dput &
    mntput...

    So I think original patch from André is enough....

    > ---------
    >
    > Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
    >
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