From: Pablo Neira Ayuso <pablo@netfilter•org>
To: Marko Jevtic <marko.jevtic@codereflect•io>
Cc: fw@strlen•de, netfilter-devel@vger•kernel.org, phil@nwl•cc,
coreteam@netfilter•org, davem@davemloft•net, edumazet@google•com,
kuba@kernel•org, pabeni@redhat•com, horms@kernel•org,
netdev@vger•kernel.org, linux-kernel@vger•kernel.org
Subject: Re: [PATCH net v3] netfilter: nft_set_rbtree: fix use count leak on transaction abort
Date: Tue, 14 Apr 2026 02:11:26 +0200 [thread overview]
Message-ID: <ad2GLmdP2wRVyd5c@chamomile> (raw)
In-Reply-To: <20260412222801.34965-1-marko.jevtic@codereflect.io>
Hi,
On Mon, Apr 13, 2026 at 12:28:01AM +0200, Marko Jevtic wrote:
> nft_rbtree_abort() does not handle elements moved to the expired list
> by inline GC during __nft_rbtree_insert(). When inline GC encounters
> expired elements during overlap detection, it calls
> nft_rbtree_gc_elem_move() which deactivates element data (decrementing
> chain/object use counts), removes the element from the rbtree, and
> queues it for deferred freeing. On commit, these elements are freed
> via nft_rbtree_gc_queue(). On abort, however, the expired list is
> ignored entirely.
>
> This leaves use counts permanently decremented after abort.
Yes, but that is expected?
Expired elements reside in priv->expired, these elements are already
deactivated, ie. removed from the rbtree and chain reference is
decremented.
From abort path, the deactivated element simply remains there until
there is a commit run that gets rid of it.
I can't make any sense of this bug report so far.
Why do you think there is a need to restore an expired element?
prev parent reply other threads:[~2026-04-14 0:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-12 22:28 [PATCH net v3] netfilter: nft_set_rbtree: fix use count leak on transaction abort Marko Jevtic
2026-04-12 22:31 ` Florian Westphal
2026-04-14 0:11 ` Pablo Neira Ayuso [this message]
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