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

From: Alexey Dobriyan
Date: Tue Jun 29 2010 - 04:45:25 EST


On Tue, Jun 29, 2010 at 12:03 AM, Kees Cook <kees.cook@xxxxxxxxxxxxx> 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.
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