Re: [PATCH] cgroup: fix possible memory leak

[Paul Menage]

On Sun, Jul 27, 2008 at 7:20 PM, Li Zefan <lizf@xxxxxxxxxxxxxx> wrote:
> There's a leak if copy_from_user() returns failure.
>
> Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>

Acked-by: Paul Menage <menage@xxxxxxxxxx>

Thanks, good catch.

> ---
>  kernel/cgroup.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/cgroup.c b/kernel/cgroup.c
> index 657f8f8..28debe4 100644
> --- a/kernel/cgroup.c
> +++ b/kernel/cgroup.c
> @@ -1424,14 +1424,17 @@ static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft,
>                if (buffer == NULL)
>                        return -ENOMEM;
>        }
> -       if (nbytes && copy_from_user(buffer, userbuf, nbytes))
> -               return -EFAULT;
> +       if (nbytes && copy_from_user(buffer, userbuf, nbytes)) {
> +               retval = -EFAULT;
> +               goto out;
> +       }
>
>        buffer[nbytes] = 0;     /* nul-terminate */
>        strstrip(buffer);
>        retval = cft->write_string(cgrp, cft, buffer);
>        if (!retval)
>                retval = nbytes;
> +out:
>        if (buffer != local_buffer)
>                kfree(buffer);
>        return retval;
> --
> 1.5.4.rc3
>
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