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 E2DC6403B11; Wed, 30 Sep 2026 19:31:09 +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=1790796671; cv=none; b=YNCKANp2DYCXigATsOaFk+rX95glJMKNaiy4+NxFmjI0EWVHUr87yRySvhStC/9/ZOPECtG39IztBDAA4ODB9dDw2FBoY0lh7hnd0xY77JgSxbf/33z9WfRJqc23f3Ru8gOiLiaqHXu0Uzaol9m62GbmXl4bz5rnyP4OwJTxIJM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796671; c=relaxed/simple; bh=8xsfU/rUvPmwcBppl9oCbrmHqRKtvx6Ep6IpkpSyAlU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HDkNH5LqUBn2Jey5btWxJrUYBoiT7yBFeZGGbuGcAuO98VfPrXDd2C9tb2vXb7lmAqFw7OC8GoUB1a74WkUh7gEmI1muYn6bHr604ZKi7ive54LEslHkZAuPAq7JKqgRQwoUhewESemzJdEBmn0Ar9jacbO9pB9lNRWItd1Cl44= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LyJa0lbL; 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="LyJa0lbL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49C4C1F000FF; Wed, 30 Sep 2026 19:31:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790796669; bh=3UbbvUtt4+pcrZfvohJS+m4Dmnu9PYWiwAzsmXwB+6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LyJa0lbLC4JGDwHkq3pRPRQHsVCxJ9pNZnR/hBFwpDdazFA8SKRTwTb5tHnhFqlPD xJClcK+z1hHuvspgWJ4+5NCkISSDPPhetlHRuki+9hmMk567xoqTSPHBQUMm9XxFR5 44lshgY2gUdklYRd1kmL9I+C4DEJhwnjQrjAYWPE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Florian Westphal , Scott Mitchell , Sasha Levin Subject: [PATCH 6.6 0993/1193] netfilter: nfnetlink_queue: nfqnl_instance GFP_ATOMIC -> GFP_KERNEL_ACCOUNT allocation Date: Wed, 30 Sep 2026 17:27:57 +0200 Message-ID: <20260930152456.303917199@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: Scott Mitchell [ Upstream commit a4400a5b343d1bc4aa8f685608515413238e7ee2 ] Currently, instance_create() uses GFP_ATOMIC because it's called while holding instances_lock spinlock. This makes allocation more likely to fail under memory pressure. Refactor nfqnl_recv_config() to drop RCU lock after instance_lookup() and peer_portid verification. A socket cannot simultaneously send a message and close, so the queue owned by the sending socket cannot be destroyed while processing its CONFIG message. This allows instance_create() to allocate with GFP_KERNEL_ACCOUNT before taking the spinlock. Suggested-by: Florian Westphal Signed-off-by: Scott Mitchell Signed-off-by: Florian Westphal Stable-dep-of: 9461613afc59 ("netfilter: nfnetlink_queue: hold nfnl mutex in event notifier") Signed-off-by: Sasha Levin --- net/netfilter/nfnetlink_queue.c | 75 +++++++++++++++------------------ 1 file changed, 34 insertions(+), 41 deletions(-) diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index cfd12124e8272..cd6cd258754d9 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -121,17 +121,9 @@ instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, u32 portid) unsigned int h; int err; - spin_lock(&q->instances_lock); - if (instance_lookup(q, queue_num)) { - err = -EEXIST; - goto out_unlock; - } - - inst = kzalloc(sizeof(*inst), GFP_ATOMIC); - if (!inst) { - err = -ENOMEM; - goto out_unlock; - } + inst = kzalloc(sizeof(*inst), GFP_KERNEL_ACCOUNT); + if (!inst) + return ERR_PTR(-ENOMEM); inst->queue_num = queue_num; inst->peer_portid = portid; @@ -141,9 +133,15 @@ instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, u32 portid) spin_lock_init(&inst->lock); INIT_LIST_HEAD(&inst->queue_list); + spin_lock(&q->instances_lock); + if (instance_lookup(q, queue_num)) { + err = -EEXIST; + goto out_unlock; + } + if (!try_module_get(THIS_MODULE)) { err = -EAGAIN; - goto out_free; + goto out_unlock; } h = instance_hashfn(queue_num); @@ -153,10 +151,9 @@ instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, u32 portid) return inst; -out_free: - kfree(inst); out_unlock: spin_unlock(&q->instances_lock); + kfree(inst); return ERR_PTR(err); } @@ -1343,7 +1340,8 @@ static int nfqnl_recv_config(struct sk_buff *skb, const struct nfnl_info *info, struct nfqnl_msg_config_cmd *cmd = NULL; struct nfqnl_instance *queue; __u32 flags = 0, mask = 0; - int ret = 0; + + WARN_ON_ONCE(!lockdep_nfnl_is_held(NFNL_SUBSYS_QUEUE)); if (nfqa[NFQA_CFG_CMD]) { cmd = nla_data(nfqa[NFQA_CFG_CMD]); @@ -1389,47 +1387,44 @@ static int nfqnl_recv_config(struct sk_buff *skb, const struct nfnl_info *info, } } + /* 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. + */ rcu_read_lock(); queue = instance_lookup(q, queue_num); if (queue && queue->peer_portid != NETLINK_CB(skb).portid) { - ret = -EPERM; - goto err_out_unlock; + rcu_read_unlock(); + return -EPERM; } + rcu_read_unlock(); if (cmd != NULL) { switch (cmd->command) { case NFQNL_CFG_CMD_BIND: - if (queue) { - ret = -EBUSY; - goto err_out_unlock; - } - queue = instance_create(q, queue_num, - NETLINK_CB(skb).portid); - if (IS_ERR(queue)) { - ret = PTR_ERR(queue); - goto err_out_unlock; - } + if (queue) + return -EBUSY; + queue = instance_create(q, queue_num, NETLINK_CB(skb).portid); + if (IS_ERR(queue)) + return PTR_ERR(queue); break; case NFQNL_CFG_CMD_UNBIND: - if (!queue) { - ret = -ENODEV; - goto err_out_unlock; - } + if (!queue) + return -ENODEV; instance_destroy(q, queue); - goto err_out_unlock; + return 0; case NFQNL_CFG_CMD_PF_BIND: case NFQNL_CFG_CMD_PF_UNBIND: break; default: - ret = -ENOTSUPP; - goto err_out_unlock; + return -EOPNOTSUPP; } } - if (!queue) { - ret = -ENODEV; - goto err_out_unlock; - } + if (!queue) + return -ENODEV; if (nfqa[NFQA_CFG_PARAMS]) { struct nfqnl_msg_config_params *params = @@ -1454,9 +1449,7 @@ static int nfqnl_recv_config(struct sk_buff *skb, const struct nfnl_info *info, spin_unlock_bh(&queue->lock); } -err_out_unlock: - rcu_read_unlock(); - return ret; + return 0; } static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { -- 2.53.0