From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7596BC46467 for ; Tue, 5 Apr 2022 12:02:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381871AbiDEL7x (ORCPT ); Tue, 5 Apr 2022 07:59:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245033AbiDEIxC (ORCPT ); Tue, 5 Apr 2022 04:53:02 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1FA46DF1; Tue, 5 Apr 2022 01:50:13 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AD66461509; Tue, 5 Apr 2022 08:50:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B479AC385A3; Tue, 5 Apr 2022 08:50:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649148612; bh=cHh6Am89UvKmAAC6DhpJgKI9IPbPSd8DeXy2OH/l794=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LN26nnnL3CWPvZxGsoNhIkn+pcnGefkZ9OJ4px2C8NGzP/pnbPFPzkPaoyZGIJNWp L7ckHdVHr1WY60OIGUqgXmPgohGLGA3jfrhu5lG5ixW2H6MZI+kkBhK27g/HkywtCl lihCKEJJlOhQ094KOD4tbi7XHR3VLdM3nDbYcY6o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yiru Xu , Pavel Skripkin , Marcel Holtmann , Sasha Levin Subject: [PATCH 5.16 0417/1017] Bluetooth: hci_serdev: call init_rwsem() before p->open() Date: Tue, 5 Apr 2022 09:22:10 +0200 Message-Id: <20220405070406.666839315@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Skripkin [ Upstream commit 9d7cbe2b9cf5f650067df4f402fdd799d4bbb4e1 ] kvartet reported, that hci_uart_tx_wakeup() uses uninitialized rwsem. The problem was in wrong place for percpu_init_rwsem() call. hci_uart_proto::open() may register a timer whose callback may call hci_uart_tx_wakeup(). There is a chance, that hci_uart_register_device() thread won't be fast enough to call percpu_init_rwsem(). Fix it my moving percpu_init_rwsem() call before p->open(). INFO: trying to register non-static key. The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator. CPU: 2 PID: 18524 Comm: syz-executor.5 Not tainted 5.16.0-rc6 #9 ... Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 assign_lock_key kernel/locking/lockdep.c:951 [inline] register_lock_class+0x148d/0x1950 kernel/locking/lockdep.c:1263 __lock_acquire+0x106/0x57e0 kernel/locking/lockdep.c:4906 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5602 percpu_down_read_trylock include/linux/percpu-rwsem.h:92 [inline] hci_uart_tx_wakeup+0x12e/0x490 drivers/bluetooth/hci_ldisc.c:124 h5_timed_event+0x32f/0x6a0 drivers/bluetooth/hci_h5.c:188 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 Fixes: d73e17281665 ("Bluetooth: hci_serdev: Init hci_uart proto_lock to avoid oops") Reported-by: Yiru Xu Signed-off-by: Pavel Skripkin Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- drivers/bluetooth/hci_serdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c index 3b00d82d36cf..4cda890ce647 100644 --- a/drivers/bluetooth/hci_serdev.c +++ b/drivers/bluetooth/hci_serdev.c @@ -305,6 +305,8 @@ int hci_uart_register_device(struct hci_uart *hu, if (err) return err; + percpu_init_rwsem(&hu->proto_lock); + err = p->open(hu); if (err) goto err_open; @@ -327,7 +329,6 @@ int hci_uart_register_device(struct hci_uart *hu, INIT_WORK(&hu->init_ready, hci_uart_init_work); INIT_WORK(&hu->write_work, hci_uart_write_work); - percpu_init_rwsem(&hu->proto_lock); /* Only when vendor specific setup callback is provided, consider * the manufacturer information valid. This avoids filling in the -- 2.34.1