From patchwork Wed Feb 21 14:57:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniil Dulov X-Patchwork-Id: 775608 Received: from mail-out.aladdin-rd.ru (mail-out.aladdin-rd.ru [91.199.251.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 239837FBC5; Wed, 21 Feb 2024 14:59:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.199.251.16 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708527555; cv=none; b=IfxdTPJN4yoCaH7OxpE0RdDMjhXzYLXGxWJfdEVGFUEavruucKNR3Mv8wqJuzdBFaSOwmrmHs+Fhl7f6L2OtvL0DiIFmAXZ3+HZi54WidmtRU0hin6pC5fc1P0G1M061RrevMCr825czOTCrDSNen99jD3dnewAvljjjUqPBvik= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708527555; c=relaxed/simple; bh=rOXs7IK7BPd47XxyU2z2y1odp+Wf1KbCWQduP9pOyt0=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CuiCS5ec7ckfYz8Si+26TUHEIhc8RXWS0Fgamh+slhvSfPBGvfefaSGfom3HqkXEkgjHGjYafuoGAlHsRAB0lay8q/MOeiQ2Kf3iytIM0AFbCUlF10b2dfZ6MlGr1u6KgEhIflXvK2hTHhPbdchpfX7sVGeQAce5p+IFJ8GKzrE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=aladdin.ru; spf=pass smtp.mailfrom=aladdin.ru; arc=none smtp.client-ip=91.199.251.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=aladdin.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=aladdin.ru From: Daniil Dulov To: Greg Kroah-Hartman , CC: Daniil Dulov , Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , Arkadiusz Bokowy , , , , Ying Hsu , Luiz Augusto von Dentz Subject: [PATCH 5.10/5.15 1/1] Bluetooth: Fix deadlock in vhci_send_frame Date: Wed, 21 Feb 2024 17:57:44 +0300 Message-ID: <20240221145744.27895-2-d.dulov@aladdin.ru> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240221145744.27895-1-d.dulov@aladdin.ru> References: <20240221145744.27895-1-d.dulov@aladdin.ru> Precedence: bulk X-Mailing-List: linux-bluetooth@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EXCH-2016-03.aladdin.ru (192.168.1.103) To EXCH-2016-01.aladdin.ru (192.168.1.101) From: Ying Hsu commit 769bf60e17ee1a56a81e7c031192c3928312c52e upstream. syzbot found a potential circular dependency leading to a deadlock: -> #3 (&hdev->req_lock){+.+.}-{3:3}: __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599 __mutex_lock kernel/locking/mutex.c:732 [inline] mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784 hci_dev_do_close+0x3f/0x9f net/bluetooth/hci_core.c:551 hci_rfkill_set_block+0x130/0x1ac net/bluetooth/hci_core.c:935 rfkill_set_block+0x1e6/0x3b8 net/rfkill/core.c:345 rfkill_fop_write+0x2d8/0x672 net/rfkill/core.c:1274 vfs_write+0x277/0xcf5 fs/read_write.c:594 ksys_write+0x19b/0x2bd fs/read_write.c:650 do_syscall_x64 arch/x86/entry/common.c:55 [inline] do_syscall_64+0x51/0xba arch/x86/entry/common.c:93 entry_SYSCALL_64_after_hwframe+0x61/0xcb -> #2 (rfkill_global_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599 __mutex_lock kernel/locking/mutex.c:732 [inline] mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784 rfkill_register+0x30/0x7e3 net/rfkill/core.c:1045 hci_register_dev+0x48f/0x96d net/bluetooth/hci_core.c:2622 __vhci_create_device drivers/bluetooth/hci_vhci.c:341 [inline] vhci_create_device+0x3ad/0x68f drivers/bluetooth/hci_vhci.c:374 vhci_get_user drivers/bluetooth/hci_vhci.c:431 [inline] vhci_write+0x37b/0x429 drivers/bluetooth/hci_vhci.c:511 call_write_iter include/linux/fs.h:2109 [inline] new_sync_write fs/read_write.c:509 [inline] vfs_write+0xaa8/0xcf5 fs/read_write.c:596 ksys_write+0x19b/0x2bd fs/read_write.c:650 do_syscall_x64 arch/x86/entry/common.c:55 [inline] do_syscall_64+0x51/0xba arch/x86/entry/common.c:93 entry_SYSCALL_64_after_hwframe+0x61/0xcb -> #1 (&data->open_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1b6/0x1bc2 kernel/locking/mutex.c:599 __mutex_lock kernel/locking/mutex.c:732 [inline] mutex_lock_nested+0x17/0x1c kernel/locking/mutex.c:784 vhci_send_frame+0x68/0x9c drivers/bluetooth/hci_vhci.c:75 hci_send_frame+0x1cc/0x2ff net/bluetooth/hci_core.c:2989 hci_sched_acl_pkt net/bluetooth/hci_core.c:3498 [inline] hci_sched_acl net/bluetooth/hci_core.c:3583 [inline] hci_tx_work+0xb94/0x1a60 net/bluetooth/hci_core.c:3654 process_one_work+0x901/0xfb8 kernel/workqueue.c:2310 worker_thread+0xa67/0x1003 kernel/workqueue.c:2457 kthread+0x36a/0x430 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 -> #0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3787 [inline] __lock_acquire+0x2d32/0x77fa kernel/locking/lockdep.c:5011 lock_acquire+0x273/0x4d5 kernel/locking/lockdep.c:5622 __flush_work+0xee/0x19f kernel/workqueue.c:3090 hci_dev_close_sync+0x32f/0x1113 net/bluetooth/hci_sync.c:4352 hci_dev_do_close+0x47/0x9f net/bluetooth/hci_core.c:553 hci_rfkill_set_block+0x130/0x1ac net/bluetooth/hci_core.c:935 rfkill_set_block+0x1e6/0x3b8 net/rfkill/core.c:345 rfkill_fop_write+0x2d8/0x672 net/rfkill/core.c:1274 vfs_write+0x277/0xcf5 fs/read_write.c:594 ksys_write+0x19b/0x2bd fs/read_write.c:650 do_syscall_x64 arch/x86/entry/common.c:55 [inline] do_syscall_64+0x51/0xba arch/x86/entry/common.c:93 entry_SYSCALL_64_after_hwframe+0x61/0xcb This change removes the need for acquiring the open_mutex in vhci_send_frame, thus eliminating the potential deadlock while maintaining the required packet ordering. Fixes: 92d4abd66f70 ("Bluetooth: vhci: Fix race when opening vhci device") Signed-off-by: Ying Hsu Signed-off-by: Luiz Augusto von Dentz [Daniil: In order to adapt this patch to branches 5.10 and 5.15 redundant fields of struct vhci_data were removed as these fields are not used in 5.10 and 5.15.] Signed-off-by: Daniil Dulov --- drivers/bluetooth/hci_vhci.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c index 31d70bad83d2..93773ec90795 100644 --- a/drivers/bluetooth/hci_vhci.c +++ b/drivers/bluetooth/hci_vhci.c @@ -11,6 +11,7 @@ #include #include +#include #include #include #include @@ -37,6 +38,7 @@ struct vhci_data { struct mutex open_mutex; struct delayed_work open_timeout; + atomic_t initialized; }; static int vhci_open_dev(struct hci_dev *hdev) @@ -68,11 +70,10 @@ static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb) memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1); - mutex_lock(&data->open_mutex); skb_queue_tail(&data->readq, skb); - mutex_unlock(&data->open_mutex); - wake_up_interruptible(&data->read_wait); + if (atomic_read(&data->initialized)) + wake_up_interruptible(&data->read_wait); return 0; } @@ -139,7 +140,8 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode) skb_put_u8(skb, 0xff); skb_put_u8(skb, opcode); put_unaligned_le16(hdev->id, skb_put(skb, 2)); - skb_queue_tail(&data->readq, skb); + skb_queue_head(&data->readq, skb); + atomic_inc(&data->initialized); wake_up_interruptible(&data->read_wait); return 0;