From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2DE0A3C10BF; Wed, 30 Sep 2026 19:13:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790795633; cv=none; b=oZc1yNxsyrvRkHGG7oHpJFMu1O1E5uBWdzpynXdLMOEqsaSKYVKflT6BkE6ICiD+aimlIB/60Bi+VOiv5grJ4DpO9y+lFCYOJhInabblcDaWnbDxJm/Ns5OIKPb9AKyuvTPsGcxUPnxaQUsGptAGtMtv+myfkBs+r4au+dDb8Mw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790795633; c=relaxed/simple; bh=Xdj2V79uha36roNYY2W2kf4ydYa3mnU9RpRWGDIqGiQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hOB21i9Q9YI7Gf9kYIPQ5lQ63VBW5nOqY0hb7neyyggxuSkmf+puK/anXwuGcXv3yPb78+xL/aA9GjhmYtbUUDdqL5+Qmf9fy1Ndlat5XEij5WNGSuK7kVK90EYlTp43j7Fi7eNHDhVDTuTnOINZvSw4U5oLBLALE2sovl6Km0E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LGdO/++B; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LGdO/++B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DF5B1F000FF; Wed, 30 Sep 2026 19:13:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790795631; bh=D9sKClUpAAqicdddhZq2A7DGhgbn1Y/TNzYSOWUHiDA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LGdO/++BvBrdlzZqGRxa5D+a7tSSQSA285XKff4tZ2c+0iyPwAUfd0+YNtjRo//if ORfyUwAhK9wZ1BxnBgbcueorKyap+aFJ9l98j2tras7woN2ba1m9Wn9JejgQwB6cqE HuSY24Qys4s/w6Bvyb1du3gvM92O7dhnl7FTjd+4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chengfeng Ye , Pablo Neira Ayuso Subject: [PATCH 6.6 0630/1193] netfilter: nf_log: unregister loggers before per-net teardown Date: Wed, 30 Sep 2026 17:21:54 +0200 Message-ID: <20260930152448.240716654@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chengfeng Ye commit 2c018cc4842c33f0c732962e2ab58635e8ae5823 upstream. nf_log_syslog and nfnetlink_log unregister their per-network namespace operations before unregistering their global logger backends. This leaves a window where a sysctl or netlink writer can rebind the still- registered logger after the per-net pre-exit callback cleared the old selection. The race looks like this: CPU 0 CPU 1 ---- ---- unregister_pernet_subsys() nf_log_unset(net, logger) net->nf.nf_loggers[pf] = NULL lock nf_log_mutex find logger in loggers[][] net->nf.nf_loggers[pf] = logger unlock nf_log_mutex nf_log_unregister(logger) lock nf_log_mutex loggers[pf][type] = NULL unlock nf_log_mutex synchronize_rcu() module exit returns module core frees backend memory Later, a sysctl read or packet logging operation can dereference the stale per-net logger pointer. Fix this by unregistering the global logger backends before tearing down per-net state. Once the global registrations are gone, later writers can no longer rebind the logger. unregister_pernet_subsys() already waits for an RCU grace period after the pre-exit callback clears the per-net selection, while nf_log_unregister() continues to cover readers of the global logger table. Apply this ordering fix to both nf_log backends that combine per-net teardown with global logger registration. Fixes: 5b023fc8d8e0 ("netfilter: enable per netns support for nf_loggers") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_log_syslog.c | 2 +- net/netfilter/nfnetlink_log.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/net/netfilter/nf_log_syslog.c +++ b/net/netfilter/nf_log_syslog.c @@ -1063,12 +1063,12 @@ err1: static void __exit nf_log_syslog_exit(void) { - unregister_pernet_subsys(&nf_log_syslog_net_ops); nf_log_unregister(&nf_ip_logger); nf_log_unregister(&nf_arp_logger); nf_log_unregister(&nf_ip6_logger); nf_log_unregister(&nf_netdev_logger); nf_log_unregister(&nf_bridge_logger); + unregister_pernet_subsys(&nf_log_syslog_net_ops); } module_init(nf_log_syslog_init); --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -1205,8 +1205,8 @@ static void __exit nfnetlink_log_fini(vo { nfnetlink_subsys_unregister(&nfulnl_subsys); netlink_unregister_notifier(&nfulnl_rtnl_notifier); - unregister_pernet_subsys(&nfnl_log_net_ops); nf_log_unregister(&nfulnl_logger); + unregister_pernet_subsys(&nfnl_log_net_ops); } MODULE_DESCRIPTION("netfilter userspace logging");