From: Florian Westphal <fw@strlen.de>
To: Bui Viet Dung <dungvn2345@gmail.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>,
Phil Sutter <phil@nwl.cc>,
netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] netfilter: nft_set_pipapo: skip transaction elements during GC
Date: Thu, 8 Oct 2026 11:05:05 +0200 [thread overview]
Message-ID: <asdcwQRmKVA6rVyZ@strlen.de> (raw)
In-Reply-To: <20261007182057.332512-1-dungvn2345@gmail.com>
Bui Viet Dung <dungvn2345@gmail.com> wrote:
> Since nft_set_commit_update() runs set commit callbacks before processing
> NEWSETELEM transactions, pipapo_gc_scan() can observe elements added by
> the transaction being committed.
>
> The scan evaluates elements in priv->clone without checking the element's
> transaction state. Expired elements are deactivated, dropped from
> priv->clone, and queued for GC reclaim via pipapo_gc_queue().
>
> When the transaction loop in nf_tables_commit() subsequently processes
> NFT_MSG_NEWSETELEM, it calls nft_setelem_activate() on an element pointer
> that has already been handed off to GC reclaim, causing a
> slab-use-after-free.
Can you send a reproducer? I don't understand how we can add
already-expired elements, it should not be permitted?
next prev parent reply other threads:[~2026-10-08 9:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-07 18:20 Bui Viet Dung
2026-10-07 19:45 ` Pablo Neira Ayuso
2026-10-08 9:05 ` Florian Westphal [this message]
2026-10-08 11:18 ` Bui Viet Dung
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=asdcwQRmKVA6rVyZ@strlen.de \
--to=fw@strlen.de \
--cc=coreteam@netfilter.org \
--cc=dungvn2345@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.org \
--cc=phil@nwl.cc \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®