From nobody Mon Sep 16 18:52:01 2024 Received: from mail-pg1-f179.google.com (mail-pg1-f179.google.com [209.85.215.179]) (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 B55A214C5A1; Tue, 23 Jul 2024 17:19:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.179 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721755148; cv=none; b=XYiKZKC4EhlaDDbgm5fLo9cxF+P1E1jhoLMBGigsao1J4qZAnMab7cVqbqMLTNHcJ9Js0lUBVSWsHlLAXDLWCn/5czD0fFWDPkTb4s3bHiVPAJsH9dMqx//w52jvUjy82G7TZvUqh+jbDn3zW5Y66CtW98zXQY0+CUD0GJrGpxI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721755148; c=relaxed/simple; bh=9s5Vi5MZuDidTPxO2XHs1LBSd+mG/mBJsPBCN5ZhRso=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HzeaeaGueSpasEqola23ooc8cj62VuivPudlML8eUIxIm+MQ/Z+z8lB/NX3l+eXAoQjAwi1qWPBoRoAHWVxuYhLk30+7EG0+9x0SSwBUOk4iyS9OCgUxantzyKvXZ/gq5yIZ59dNaZwlFRayUfCc37aIb4PwaFhwsYhIIvAqwm4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=T5hiqh9S; arc=none smtp.client-ip=209.85.215.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="T5hiqh9S" Received: by mail-pg1-f179.google.com with SMTP id 41be03b00d2f7-7a23fbb372dso782742a12.0; Tue, 23 Jul 2024 10:19:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1721755146; x=1722359946; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=7PESp8ToMvs18L2DY1lc9MxMw8bEbHV0v8oTGSy6LMk=; b=T5hiqh9ShUZdjARLEpaMLZcI65gRZZ7cAWTcKSNxRQtbIDMTSmqYXvLq1nGuBSR0qI OvHU7/59GYlVs11OPnG1pCxlOloy05ghAXPpjzC4zuR5aALPCdzNxtysEa1NMzYg79/E MEzZOyYa4G9OweW7/k/o3gQSLP51vqI7SlXQBzujzWblYSD/SLDTns7HInZ40I/cpgCB mHywl6qvd3zEsPcPj1BVsFgX1XVwtt4oB0p5xmf6ZxbHf45jmLn4UM6bcrWOCC83aoP8 eN+xZekbQ7mEy/btXRxswJo/UhSF3TUwLK4LjuGZaFn61jwjePhJNm79kOBWd2lYs+U/ em0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721755146; x=1722359946; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=7PESp8ToMvs18L2DY1lc9MxMw8bEbHV0v8oTGSy6LMk=; b=QA45ICRLk8T3bf9v0JD4NFodasYqd/r9t5phXHgBNHheR51/cUSr8Qbn0apZw28yvq INy9e507XX200xnxss2LLL/LOkKewrqaSpMGqtXlRg6kUl+PH3pECVkHuTcxqYq66y+P oCohW/brPdXkUqNdFsPlRFUcuPECEndi9qowLEFaoaiCjzeZ7r3kKSp4gT4EBUyjOsHa wbof0e6fm4OGMGoB3R3a5IUv2Pt/WYugppOLB4+pOI2fwRxoT3NqWWqxiEMa7mr3IQqe 7DFy+DWN9wqDAu2qqfRei3VwV38J/W6SJi+whBsmTN8kgsCZUuZVmtoF/pfzh0gN4bXb 0BTQ== X-Forwarded-Encrypted: i=1; AJvYcCVXz6CoTpb1FvciJFXFTec4VaA6o2y9ZjFkzOtfYhWELn5bm+wPDxOtuGUOVhgNOtBCF+HWk7SZRhczfQPneU0iMuv8BaKZa+ca8Tw9dloauT8sS1kFwTK+L4+rwI1XOh8u435OGR0Oy26ZYB5mQqbNW7pYDv+PfPtv+yCa X-Gm-Message-State: AOJu0YwZI+K6JgZRXs/6amygpbtzFhgsixP4IlpWGG2JwN7B5beK0STv iRiq8jSiAudpIriVtrsOEbpsE/fe4rCqBL4RbgpK7mvxxuTse+yB X-Google-Smtp-Source: AGHT+IH/x0EB2OW34wSIoGSpIBNCX6QxTmCPilyFpkTLbvSMOGQPUxFAfFsR5aZVR1HBIrLkMPEiAA== X-Received: by 2002:a17:90a:7841:b0:2c9:75c6:32dc with SMTP id 98e67ed59e1d1-2cd85c25249mr3762641a91.1.1721755146006; Tue, 23 Jul 2024 10:19:06 -0700 (PDT) Received: from localhost.localdomain ([118.32.98.101]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2cb76a5fc6csm10705800a91.0.2024.07.23.10.19.02 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 23 Jul 2024 10:19:05 -0700 (PDT) From: Yunseong Kim To: Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org, Yeoreum Yun Subject: [PATCH] Bluetooth: hci_core: fix suspicious RCU usage in hci_conn_drop() Date: Wed, 24 Jul 2024 02:17:57 +0900 Message-ID: <20240723171756.13755-2-yskelg@gmail.com> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Protection from the queuing operation is achieved with an RCU read lock to avoid calling 'queue_delayed_work()' after 'cancel_delayed_work()', but this does not apply to 'hci_conn_drop()'. commit deee93d13d38 ("Bluetooth: use hdev->workqueue when queuing hdev->{cmd,ncmd}_timer works") The situation described raises concerns about suspicious RCU usage in a corrupted context. CPU 1 CPU 2 hci_dev_do_reset() synchronize_rcu() hci_conn_drop() drain_workqueue() <-- no RCU read protection during queuing. --> queue_delayed_work() It displays a warning message like the following Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D WARNING: suspicious RCU usage 6.10.0-rc6-01340-gf14c0bb78769 #5 Not tainted Tested-by: Yunseong Kim ----------------------------- net/mac80211/util.c:4000 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active =3D 2, debug_locks =3D 1 2 locks held by syz-executor/798: #0: ffff800089a3de50 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x28/0x40 net/core/rtnetlink.c:79 stack backtrace: CPU: 0 PID: 798 Comm: syz-executor Not tainted 6.10.0-rc6-01340-gf14c0bb78769 #5 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace.part.0+0x1b8/0x1d0 arch/arm64/kernel/stacktrace.c:317 dump_backtrace arch/arm64/kernel/stacktrace.c:323 [inline] show_stack+0x34/0x50 arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xf0/0x170 lib/dump_stack.c:114 dump_stack+0x20/0x30 lib/dump_stack.c:123 lockdep_rcu_suspicious+0x204/0x2f8 kernel/locking/lockdep.c:6712 ieee80211_check_combinations+0x71c/0x828 [mac80211] ieee80211_check_concurrent_iface+0x494/0x700 [mac80211] ieee80211_open+0x140/0x238 [mac80211] __dev_open+0x270/0x498 net/core/dev.c:1474 __dev_change_flags+0x47c/0x610 net/core/dev.c:8837 dev_change_flags+0x98/0x170 net/core/dev.c:8909 devinet_ioctl+0xdf0/0x18d0 net/ipv4/devinet.c:1177 inet_ioctl+0x34c/0x388 net/ipv4/af_inet.c:1003 sock_do_ioctl+0xe4/0x240 net/socket.c:1222 sock_ioctl+0x4cc/0x740 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __arm64_sys_ioctl+0x184/0x218 fs/ioctl.c:893 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x90/0x2e8 arch/arm64/kernel/syscall.c:48 el0_svc_common.constprop.0+0x200/0x2a8 arch/arm64/kernel/syscall.c:131 el0_svc+0x48/0xc0 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x120/0x130 arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x198 arch/arm64/kernel/entry.S:598 This patch attempts to fix that issue with the same convention. Cc: stable@vger.kernel.org # v6.1+ Fixes: deee93d13d38 ("Bluetooth: use hdev->workqueue when queuing hdev-> {cmd,ncmd}_timer works") Signed-off-by: Yeoreum Yun Tested-by: Yunseong Kim Signed-off-by: Yunseong Kim --- include/net/bluetooth/hci_core.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_c= ore.h index 31020891fc68..111509dc1a23 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -1572,8 +1572,13 @@ static inline void hci_conn_drop(struct hci_conn *co= nn) } =20 cancel_delayed_work(&conn->disc_work); - queue_delayed_work(conn->hdev->workqueue, - &conn->disc_work, timeo); + + rcu_read_lock(); + if (!hci_dev_test_flag(conn->hdev, HCI_CMD_DRAIN_WORKQUEUE)) { + queue_delayed_work(conn->hdev->workqueue, + &conn->disc_work, timeo); + } + rcu_read_unlock(); } } =20 --=20 2.45.2