On Mon, 28 May 2007 17:41:57 +0400
Alexey Dobriyan <[EMAIL PROTECTED]> wrote:

> Signed-off-by: Alexey Dobriyan <[EMAIL PROTECTED]>

Better changelogs, please.

> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -204,12 +204,17 @@ static int proc_pid_environ(struct task_
>       int res = 0;
>       struct mm_struct *mm = get_task_mm(task);
>       if (mm) {
> -             unsigned int len = mm->env_end - mm->env_start;
> +             unsigned int len;
> +
> +             res = -ESRCH;
> +             if (!ptrace_may_attach(task))
> +                     goto out;
> +
> +             len  = mm->env_end - mm->env_start;
>               if (len > PAGE_SIZE)
>                       len = PAGE_SIZE;
>               res = access_process_vm(task, mm->env_start, buffer, len, 0);
> -             if (!ptrace_may_attach(task))
> -                     res = -ESRCH;
> +out:
>               mmput(mm);
>       }
>       return res;

What's wrong with the existing code?  It's a bit dopey-looking and can, I
guess, permit a task to cause a pagefault in an mm which it doesn't have
permission to read from.  But is there some more serious problem being
fixed here?

I shouldn't have to ask this stuff.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to