Re: [PATCH] be paranoid about closed stdin/stdout/stderr

From: Johannes Sixt <j.sixt@viscovery.net>
Date: Aug 27, 2008, 06:35 UTC
Message-ID: <48B4F5C4.9020404@viscovery.net>
In-Reply-To: <48B44C61.2020206@gnu.org>

Paolo Bonzini schrieb:

Show 14 quoted lines

> Junio C Hamano wrote:
>> Johannes Sixt <j.sixt@viscovery.net> writes:
>>
>>> Paolo Bonzini schrieb:
>>>> +	/*
>>>> +	 * Always open file descriptors 0/1/2 to avoid clobbering files
>>>> +	 * in die().  It also avoids not messing up when the pipes are
>>>> +	 * dup'ed onto stdin/stdout/stderr in the child processes we spawn.
>>>> +	 */
>>> I see your point, but I don't have an opinion whether this stretch is
>>> necessary.
>> This is going too far.  Have you seen any other sane program that do this?
> 
> Busybox.  But it runs setuid, as Steven pointed out.

I straced tee (it was the only tool I found that opens files for writing without also opening some for reading). If one of 0,1,2 is closed, it *does* dup() the fd that it is going to write.

Don't you now feel like Reg in "Life of Brian":

"All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us?"

;)

-- Hannes