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 4CD8550B437; Wed, 30 Sep 2026 15:55:33 +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=1790783738; cv=none; b=TuIZ0sWynHrhUEE+WtM7adlKsebi7usW9OngvP5xjjtIPn0dUwCZDaOTNdY0uZuBnxc0EnwMH18wI/sUWy3Jd3MVRqGLjedlutRodwKK6KSgXHZGzshQJrigt1t86J5Q34EK1OrDnedpsiYgRg0tF74VWfRs9LFnPF+qQwYl7sQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790783738; c=relaxed/simple; bh=O1LM8T3hoxh1KBwlUyyPJkTRgV5XqwlSbairZkwzfd4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hJ0WYtV3MEJB1GjByNYo6J6MFV8EbrAIxL9UXkotwvzhW0n783Hej8w7HcCLN3fgJochpAsVQYQaJBe8v1l/aFxadMtV7m8WvNDh0jtMWtHL6Q93DsCJT/ngM2vLYFXQEf1YoKmpwOABmVFX870l8AMDLvoscvCSC3rpW/37sf4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=f8DPL3pV; 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="f8DPL3pV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B57311F00893; Wed, 30 Sep 2026 15:55:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790783733; bh=HtS/U6DIeAbpLpug5zrVwqRJLXD+32kuViABQALoLX4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=f8DPL3pVd7A6jemH041z9XirZJIzUgg4ZEEIDgTW469mMtJEWT/rdRiS3XNOD6e/j fEejpjjvzF5kuut7HUG2JPkaPnrvP1T6g3H3xx1InpJHZ2f0WnYAJgVtEieqwvHWLU koU+891coeVz4ZRZnb3ZWbNELGsVbvM3sIff1CHE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Florian Westphal , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 5.10 496/595] netfilter: nfnetlink_queue: hold nfnl mutex in event notifier Date: Wed, 30 Sep 2026 17:26:29 +0200 Message-ID: <20260930152358.362713568@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152347.700140858@linuxfoundation.org> References: <20260930152347.700140858@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal [ Upstream commit 9461613afc59acef44a0071b0dd5075f6e993ffe ] We must serialize the release notifier and the config netlink function. A concurrent thread can issue close() which can call the release function while unrelated socket processes UNBIND request for same portid: Oops: general protection fault, [..] RIP: 0010:__instance_destroy+0x60/0x210 [nfnetlink_queue] Call Trace: nfqnl_recv_config+0x9b0/0xdc0 [nfnetlink_queue] nfnetlink_rcv_msg+0x7c2/0xeb0 ? __pfx_nfnetlink_rcv_msg+0x10/0x10 After this, parallel UNBIND and URELEASE events are impossible. This change isn't nice, but its the shortest fix given instances are not refcounted and the nfnetlink config callback drops the rcu read lock early due to need for sleeping allocations. Fixes: 7af4cc3fa158 ("[NETFILTER]: Add "nfnetlink_queue" netfilter queue handler over nfnetlink") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nfnetlink_queue.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 5936eab2a9415..8c40a934f0e44 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -984,6 +984,7 @@ nfqnl_rcv_nl_event(struct notifier_block *this, if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) { int i; + nfnl_lock(NFNL_SUBSYS_QUEUE); /* destroy all instances for this portid */ spin_lock(&q->instances_lock); for (i = 0; i < INSTANCE_BUCKETS; i++) { @@ -997,6 +998,7 @@ nfqnl_rcv_nl_event(struct notifier_block *this, } } spin_unlock(&q->instances_lock); + nfnl_unlock(NFNL_SUBSYS_QUEUE); } return NOTIFY_DONE; } @@ -1317,9 +1319,9 @@ static int nfqnl_recv_config(struct net *net, struct sock *ctnl, /* Lookup queue under RCU. After peer_portid check (or for new queue * in BIND case), the queue is owned by the socket sending this message. - * A socket cannot simultaneously send a message and close, so while - * processing this CONFIG message, nfqnl_rcv_nl_event() (triggered by - * socket close) cannot destroy this queue. Safe to use without RCU. + * nfqnl_rcv_nl_event() will block on the nfnl subsys mutex that is + * held by the caller, so the queue cannot be destroyed in parallel, + * even after we drop the RCU read lock. */ rcu_read_lock(); queue = instance_lookup(q, queue_num); -- 2.53.0