Re: Horrible denial of service bug in autmount 5

["H. Peter Anvin" <hpa@zytor.com>]

Ian Kent wrote:
> On Fri, 2008-06-20 at 16:24 +0100, Anton Altaparmakov wrote:
>> Which means that in /proc/*/cmdline the string that appears is "pwf- 
>> amnt" (as we override argv[0] in the exec call to that effect) thus  
>> the is_automount_running() function does not find the literal string  
>> "automount" in there and we can run it as many times as we want (which  
>> is once per user).
> 
> Why do you need to run one instance per user?
> What does it get you that using a single source common global map
> doesn't provide?

Okay, I'm confused... what reason could there *possibly* be for 
searching /proc/*/cmdline? If there is a need for a mutex of some sort, 
one should typically create a /var/run directory and put in lock files, 
or some other solution to test the mutexing explicitly.  grepping ps, in 
effect, is hardly a good idea, to put it gently.

	-hpa