Re: [PATCH -rc7 1/1] netpoll: Fix a leak-n-bug in netpoll_cleanup()

[David Miller <davem@davemloft.net>]

From: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Date: Wed, 04 Jul 2007 16:36:41 +0530

> From: Satyam Sharma <ssatyam@cse.iitk.ac.in>
> 
> [1/1] netpoll: Fix a leak-n-bug in netpoll_cleanup()
> 
> 93ec2c723e3f8a216dde2899aeb85c648672bc6b applied excessive duct tape to
> the netpoll beast's netpoll_cleanup(), thus substituting one leak with
> another, and opening up a little buglet :-)
> 
> net_device->npinfo (netpoll_info) is a shared and refcounted object and
> cannot simply be set NULL the first time netpoll_cleanup() is called.
> Otherwise, further netpoll_cleanup()'s see np->dev->npinfo == NULL and
> become no-ops, thus leaking. And it's a bug too: the first call to
> netpoll_cleanup() would thus (annoyingly) "disable" other (still alive)
> netpolls too. Maybe nobody noticed this because netconsole (only user
> of netpoll) never supported multiple netpoll objects earlier.
> 
> This is a trivial and obvious one-line fixlet.
> 
> Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>

Applied to net-2.6.23, I'll forward this on to -stable too.

Thanks.