Re: [PATCH] sanitize task->comm to avoid leaking escape codes

Alexey Dobriyan
2010-06-29T08:45:21Z

On Tue, Jun 29, 2010 at 12:03 AM, Kees Cook <kees.cook@canonical.com> wrote:
> On Mon, Jun 28, 2010 at 01:00:28PM -0700, Andrew Morton wrote:
>> Surely it would be better to fix the tools which display this info
>> rather than making the kernel tell fibs.
>
> The strncpy in get_task_comm() is totally wrong -- it's testing the length
> of task->comm.

It also fills not just any buffer but buffer which is TASK_COMM_LEN byte wide.

> Why should get_task_comm not take a destination buffer length argument?

If you pass too small, you needlessly truncate output.
If you pass too large, you waste space.