From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp134-32.sina.com.cn (smtp134-32.sina.com.cn [180.149.134.32]) (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 59033BA45 for ; Sat, 30 Nov 2024 00:00:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=180.149.134.32 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732924851; cv=none; b=in5zif+/68YQn+51+TXM0ElOlLXXRQHKl6nbK6nAnJ/rQkjZEDl7lVKsbmJ2caiCky8WBiXxdqOwIh1YGwRQziGy3dS0D77sqFdRSmQYgsmYwXKqfgkxKQXrb7lMKzehP2wiFP8XfUN6GTOx8ztVksB0yBcGV2WZsY+U9WPW9gE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732924851; c=relaxed/simple; bh=09bEussHxUAV3cOmDbWiHlgo9iV5iQfyUuucrotFwsE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=c+/CWyecyYRfFW3mDbE9sbQcyjOboDuCIUrOOHwfyPRpmVYz13GTe6HHBoZl8fPDSi51OTYjcwjCcLwCVuSKxRMjyfDGoxzmdVWmvgZe/MtNQ/bQBw4r6GUXpdoEAGrzzcd8YwWkLkT584Wp+094sQV2G7/y+xfdRdXGlP2xhUA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; arc=none smtp.client-ip=180.149.134.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([113.118.64.216]) by sina.com (10.185.250.21) with ESMTP id 674A551000003F22; Fri, 30 Nov 2024 07:58:13 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 6514623408373 X-SMAIL-UIID: C78C7330846E4034920DE679090D4BE3-20241130-075813-1 From: Hillf Danton To: syzbot Cc: frederic@kernel.org, linux-kernel@vger.kernel.org, Aleksandr Nogikh , Tejun Heo , syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [kernel?] KCSAN: data-race in kick_pool / wq_worker_running Date: Sat, 30 Nov 2024 07:58:00 +0800 Message-Id: <20241129235800.2177-1-hdanton@sina.com> In-Reply-To: <6749d1e2.050a0220.253251.00b7.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Fri, 29 Nov 2024 06:38:26 -0800 > syzbot found the following issue on: > > HEAD commit: 7af08b57bcb9 Merge tag 'trace-v6.13-2' of git://git.kernel.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=10a39f5f980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=77174711582263a3 > dashboard link: https://syzkaller.appspot.com/bug?extid=f8761b2f358f6a1dec5e > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/13ed5c4111d5/disk-7af08b57.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/b14531c093bd/vmlinux-7af08b57.xz > kernel image: https://storage.googleapis.com/syzbot-assets/0ddfac565b6b/bzImage-7af08b57.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+f8761b2f358f6a1dec5e@syzkaller.appspotmail.com > > ================================================================== > BUG: KCSAN: data-race in kick_pool / wq_worker_running > > read-write to 0xffff888237d2e8a4 of 4 bytes by task 3377 on cpu 1: > wq_worker_running+0x98/0x130 kernel/workqueue.c:1400 > schedule_timeout+0xb8/0x160 kernel/time/sleep_timeout.c:99 > do_wait_for_common kernel/sched/completion.c:95 [inline] > __wait_for_common kernel/sched/completion.c:116 [inline] > wait_for_common+0xfb/0x1c0 kernel/sched/completion.c:127 > usb_start_wait_urb+0xdc/0x190 drivers/usb/core/message.c:64 > usb_internal_control_msg drivers/usb/core/message.c:103 [inline] > usb_control_msg+0x182/0x240 drivers/usb/core/message.c:154 > get_port_status drivers/usb/core/hub.c:604 [inline] > hub_ext_port_status+0xbf/0x480 drivers/usb/core/hub.c:621 > usb_hub_port_status drivers/usb/core/hub.c:671 [inline] > port_event drivers/usb/core/hub.c:5714 [inline] > hub_event+0x538/0x2910 drivers/usb/core/hub.c:5903 > process_one_work kernel/workqueue.c:3229 [inline] > process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310 > worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391 > kthread+0x1d1/0x210 kernel/kthread.c:389 > ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > read to 0xffff888237d2e8a4 of 4 bytes by task 3399 on cpu 0: > need_more_worker kernel/workqueue.c:934 [inline] /* * Need to wake up a worker? Called from anything but currently * running workers. * * Note that, because unbound workers never contribute to nr_running, this * function will always return %true for unbound pools as long as the * worklist isn't empty. */ static bool need_more_worker(struct worker_pool *pool) { return !list_empty(&pool->worklist) && !pool->nr_running; } Given bound workers only considered wrt nr_running, this report can be safely dropped/ignored as data race is ruled out for them. > kick_pool+0x4d/0x2c0 kernel/workqueue.c:1240 > __queue_work+0x8bb/0xb40 kernel/workqueue.c:2340 > queue_work_on+0xd3/0x180 kernel/workqueue.c:2390 > wg_queue_enqueue_per_peer_tx+0x124/0x260 drivers/net/wireguard/queueing.h:188 > wg_packet_encrypt_worker+0xa00/0xbb0 drivers/net/wireguard/send.c:305 > process_one_work kernel/workqueue.c:3229 [inline] > process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310 > worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391 > kthread+0x1d1/0x210 kernel/kthread.c:389 > ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > value changed: 0x00000000 -> 0x00000001 > > Reported by Kernel Concurrency Sanitizer on: > CPU: 0 UID: 0 PID: 3399 Comm: kworker/0:4 Not tainted 6.12.0-syzkaller-10689-g7af08b57bcb9 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 > Workqueue: wg-crypt-wg1 wg_packet_encrypt_worker > ================================================================== > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup >