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

From: Pavel Emelianov
Date: Wed Apr 18 2007 - 04:27:59 EST


Evgeniy Polyakov wrote:
> On Wed, Apr 18, 2007 at 12:16:18PM +0400, Pavel Emelianov (xemul@xxxxx) 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.
>

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/