Messages in this thread | | | Date | Mon, 07 Jul 2014 19:35:05 -0700 (PDT) | Subject | Re: [PATCH net-next v1 2/2] netpoll: avoid reference leaks | From | David Miller <> |
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From: David Decotigny <decot@googlers.com> Date: Mon, 30 Jun 2014 16:50:10 -0700
> This ensures that the ndo_netpoll_cleanup callback is called for every > device that provides one. Otherwise there is a risk of reference leak > with bonding for example, which depends on this callback to cleanup > the slaves' references to netpoll info. > > Tested: > see patch "netpoll: fix use after free" > > Signed-off-by: David Decotigny <decot@googlers.com>
I definitely don't understand this.
Why would we call the cleanup function of an object before it's reference count hits zero? It is exactly the act of reaching a zero refcount which should trigger invoking the cleanup callback.
If a refcount is being released in another location without checking if it hits zero and invoking the cleanup if so, _THAT_ is the bug.
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