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 A87A1426D2E; Wed, 23 Sep 2026 14:43:30 +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=1790174611; cv=none; b=tl3oCFzrR4icgrgKXzLnsIty0Kme4x7RI7m6xMgy7Va8nu9QJ08WjmQGTdJ/FrgwcXZIQuR4cB5ilfLPUiF0DVxXVM7dkFJ3hQwt5QaGiEwSsGwJSev6e9g3gd7zCRRb8yxnWnX59o+HIXfTbHeeZlp7ELTOoiXrVKo6qk07PFs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790174611; c=relaxed/simple; bh=TgP7Q1saVvGXZRsyyix6ZUm+fFc8+3tk775Q7lImb/k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FGO+m1ZrPCR+6YSYE0keGbsb+WzgeQJWv0du11UklxTz3VzAe8oOOGKxJgupfJ27Dase3yU9U7d2klwyUSR1gQQLpEaJdfjauV/2MljQZnyisLtwBPTWglltt+tB+NUe+ZTeMBL6y0OE/aLCMTVImWr5B9EHZXJpnt6dfhnKhok= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VvPTxe+f; 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="VvPTxe+f" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EDF8A1F000FF; Wed, 23 Sep 2026 14:43:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790174610; bh=yYOsC3BLRpy1eDIvLaeeLImBGVGTIRSvBMiXD0YB0yY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VvPTxe+f78Gp4zykycGLNly4jDE64S777ZuJ5gQErO0dK42GS1PiG7VmXcMq98Rj0 q2BtO8Gx8EDcuJDwN3abT/tscoghbntEWLVrL33bzl/CgXgnPDi69j15ayaJaXmcak NjM/P6u6SZUAbOGiJitsiAsyGmo8Tyfwe/I7yCFU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+b6919040d9958e2fc1ae@syzkaller.appspotmail.com, ThangNN99 , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.18 141/398] Bluetooth: hci_core: Fix queuing tx_work after workqueue is drained Date: Wed, 23 Sep 2026 16:03:35 +0200 Message-ID: <20260923140647.087312837@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: ThangNN99 [ Upstream commit 6610c6fe4b8936c232048e6049bf77c70a6f759c ] hci_send_acl(), hci_send_sco() and hci_send_iso() queue hdev->tx_work unconditionally. They can run from the L2CAP/SCO/ISO socket send path while hci_dev_close_sync() is draining hdev->workqueue (HCIDEVDOWN racing with a socket write). Since that queue_work() is not chained work from the tx_work worker itself, __queue_work() sees the queue marked __WQ_DRAINING, warns "cannot queue %ps on wq %s", and drops the work: WARNING: CPU: 1 PID: 5985 at kernel/workqueue.c:2352 __queue_work Call Trace: queue_work_on l2cap_chan_send l2cap_sock_sendmsg ... hci_dev_close_sync() already sets HCI_CMD_DRAIN_WORKQUEUE before draining, but only hci_cmd_work() and handle_cmd_cnt_and_timer() check it before queuing. Route the tx_work producers through the same guard via a shared hci_sched_tx() helper. Fixes: 525daaea459f ("Bluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device close") Reported-by: syzbot+b6919040d9958e2fc1ae@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b6919040d9958e2fc1ae Signed-off-by: ThangNN99 Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/hci_core.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 447a7ebcdf62f..31c668ad99366 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -3273,6 +3273,17 @@ static void hci_queue_acl(struct hci_chan *chan, struct sk_buff_head *queue, bt_dev_dbg(hdev, "chan %p queued %d", chan, skb_queue_len(queue)); } +/* Queue hdev->tx_work, unless hdev->workqueue is being drained by + * hci_dev_close_sync(), which would otherwise WARN and drop the work. + */ +static void hci_sched_tx(struct hci_dev *hdev) +{ + rcu_read_lock(); + if (!hci_dev_test_flag(hdev, HCI_CMD_DRAIN_WORKQUEUE)) + queue_work(hdev->workqueue, &hdev->tx_work); + rcu_read_unlock(); +} + void hci_send_acl(struct hci_chan *chan, struct sk_buff *skb, __u16 flags) { struct hci_dev *hdev = chan->conn->hdev; @@ -3281,7 +3292,7 @@ void hci_send_acl(struct hci_chan *chan, struct sk_buff *skb, __u16 flags) hci_queue_acl(chan, &chan->data_q, skb, flags); - queue_work(hdev->workqueue, &hdev->tx_work); + hci_sched_tx(hdev); } /* Send SCO data */ @@ -3306,7 +3317,7 @@ void hci_send_sco(struct hci_conn *conn, struct sk_buff *skb) bt_dev_dbg(hdev, "hcon %p queued %d", conn, skb_queue_len(&conn->data_q)); - queue_work(hdev->workqueue, &hdev->tx_work); + hci_sched_tx(hdev); } /* Send ISO data */ @@ -3377,7 +3388,7 @@ void hci_send_iso(struct hci_conn *conn, struct sk_buff *skb) hci_queue_iso(conn, &conn->data_q, skb); - queue_work(hdev->workqueue, &hdev->tx_work); + hci_sched_tx(hdev); } /* ---- HCI TX task (outgoing data) ---- */ -- 2.53.0