From patchwork Mon Aug 29 14:58:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 12958003 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 2C84AECAAD2 for ; Mon, 29 Aug 2022 14:58:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229498AbiH2O6u (ORCPT ); Mon, 29 Aug 2022 10:58:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229453AbiH2O6t (ORCPT ); Mon, 29 Aug 2022 10:58:49 -0400 Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EFA8986C33 for ; Mon, 29 Aug 2022 07:58:46 -0700 (PDT) Received: from fsav115.sakura.ne.jp (fsav115.sakura.ne.jp [27.133.134.242]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 27TEwGpj081025; Mon, 29 Aug 2022 23:58:16 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav115.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav115.sakura.ne.jp); Mon, 29 Aug 2022 23:58:16 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav115.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 27TEwFNw081022 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Mon, 29 Aug 2022 23:58:15 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Message-ID: <376d3dd4-725a-a212-2701-09a80b7d3915@I-love.SAKURA.ne.jp> Date: Mon, 29 Aug 2022 23:58:12 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: [PATCH] Bluetooth: hci_{ldisc,serdev}: check percpu_init_rwsem() failure Content-Language: en-US To: Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , Ronald Tschalar , Lukas Wunner References: <000000000000bd19720591aac025@google.com> <0000000000003a22d605934b6722@google.com> Cc: syzbot , syzkaller-bugs@googlegroups.com, "linux-bluetooth@vger.kernel.org" From: Tetsuo Handa In-Reply-To: <0000000000003a22d605934b6722@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org syzbot is reporting NULL pointer dereference at hci_uart_tty_close() [1], for rcu_sync_enter() is called without rcu_sync_init() due to hci_uart_tty_open() ignoring percpu_init_rwsem() failure. While we are at it, fix that hci_uart_register_device() ignores percpu_init_rwsem() failure and hci_uart_unregister_device() does not call percpu_free_rwsem(). Link: https://syzkaller.appspot.com/bug?extid=576dfca25381fb6fbc5f [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Fixes: 67d2f8781b9f00d1 ("Bluetooth: hci_ldisc: Allow sleeping while proto locks are held.") Fixes: d73e172816652772 ("Bluetooth: hci_serdev: Init hci_uart proto_lock to avoid oops") --- drivers/bluetooth/hci_ldisc.c | 7 +++++-- drivers/bluetooth/hci_serdev.c | 10 +++++++--- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index f537673ede17..865112e96ff9 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -493,6 +493,11 @@ static int hci_uart_tty_open(struct tty_struct *tty) BT_ERR("Can't allocate control structure"); return -ENFILE; } + if (percpu_init_rwsem(&hu->proto_lock)) { + BT_ERR("Can't allocate semaphore structure"); + kfree(hu); + return -ENOMEM; + } tty->disc_data = hu; hu->tty = tty; @@ -505,8 +510,6 @@ static int hci_uart_tty_open(struct tty_struct *tty) INIT_WORK(&hu->init_ready, hci_uart_init_work); INIT_WORK(&hu->write_work, hci_uart_write_work); - percpu_init_rwsem(&hu->proto_lock); - /* Flush any pending characters in the driver */ tty_driver_flush_buffer(tty); diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c index c0e5f42ec6b7..f16fd79bc02b 100644 --- a/drivers/bluetooth/hci_serdev.c +++ b/drivers/bluetooth/hci_serdev.c @@ -310,11 +310,12 @@ int hci_uart_register_device(struct hci_uart *hu, serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops); + if (percpu_init_rwsem(&hu->proto_lock)) + return -ENOMEM; + err = serdev_device_open(hu->serdev); if (err) - return err; - - percpu_init_rwsem(&hu->proto_lock); + goto err_rwsem; err = p->open(hu); if (err) @@ -389,6 +390,8 @@ int hci_uart_register_device(struct hci_uart *hu, p->close(hu); err_open: serdev_device_close(hu->serdev); +err_rwsem: + percpu_free_rwsem(&hu->proto_lock); return err; } EXPORT_SYMBOL_GPL(hci_uart_register_device); @@ -410,5 +413,6 @@ void hci_uart_unregister_device(struct hci_uart *hu) clear_bit(HCI_UART_PROTO_READY, &hu->flags); serdev_device_close(hu->serdev); } + percpu_free_rwsem(&hu->proto_lock); } EXPORT_SYMBOL_GPL(hci_uart_unregister_device);