Subject: Re: [NETLINK] Don't attach callback to a going-away netlink socket

From: Pavel Emelianov <[email-masked]>
Date: Wed, 18 Apr 2007 12:32:40 +0400

Evgeniy Polyakov wrote:
> On Wed, Apr 18, 2007 at 12:16:18PM +0400, Pavel Emelianov ([email-masked]) wrote:
>> Sorry, I forgot to put netdev and David in Cc when I first sent it.
>>
>> There is a race between netlink_dump_start() and netlink_release()
>> that can lead to the situation when a netlink socket with non-zero
>> callback is freed.
> 
> Out of curiosity, why not to fix a netlink_dump_start() to remove
> callback in error path, since in 'no-error' path it removes it in

Error path is not relevant here. The problem is that we
keep a calback on a socket that is about to be freed.

> netlink_dump().
> 
> And, btw, can release method be called while socket is being used, I
> thought about proper reference counters should prevent this, but not
> 100% sure with RCU dereferencing of the descriptor.
>