From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3124841DE02; Mon, 24 Aug 2026 12:57:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787576239; cv=none; b=FP0a9BnfZ579qfjuAbLVrT4/2lreGHm3WatDnU4UXZwDtJZIyTp/N45n2XMFOlx0OoOWrHaTInmuk83ZhqXrlp0MfePhWcrZEGZl4KWtIWrvVCHU/qAjEh6kFD9xqmerKqMZahpzcZQC9gKYr0rDJ4H3e3D6ex3HtU1VlliHgOc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787576239; c=relaxed/simple; bh=gFPkcIHnQkRgZ6LvoT82P7KXrjaxtmSA5hYHJkD/53k=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=pQinPk8FnwiXnKbVP/KVH0DZer+NIIh5bsq9r67SVdr6yiT+3lpGO9ujfSMlw64Q+B+Tb46//QyQDj0autzVtWAdzZUaGTTN87AjbXilNZZqZCfBHOTE9uytoa1f+pprdMAsX6Wzz+jqmqL9DCxr81SbxGeBFyGHF0N6GCC5UrA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UELVG1hp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UELVG1hp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D244C1F000E9; Mon, 24 Aug 2026 12:57:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787576237; bh=wCQGBGKrnXzElrElzJa+hggu/yGdQXuY5mcnoZzygSg=; h=Date:Subject:To:References:From:In-Reply-To; b=UELVG1hprXVRRgMB5RGtVROPuTKxv2LSMQF9qPKNg33hKdTyfASd75+SI4DupNVWb jhESm3EATnoBEvg7egA1HEGZIQ8hY2Q+RDVDYDOXI9ZjE7nmmrxtl6v4LTeks40GYd so7o+nDOjGeAq2z6p7MW/AYlOKW30CF1Bw5Mcet7tEBfoiCXLoL0oWdiO9JUfvzwim pspPheZ57oQncrkDKoC3uaJvSmTqWHV0RLbdibb2ntdakLqmdodJXei0LRtYy5Meko z5T+/mUnwH5O6iRRlgvMZtEGTT/0pUYtRUGsZuLPmJV/3X4Sj1Zp/8BFT2hZ+oH+dW z3gMl3TbIf6Jw== Message-ID: <0e69abdc-0127-45dc-9bc1-bf48772cc7ea@kernel.org> Date: Mon, 24 Aug 2026 14:57:12 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [virt?] INFO: trying to register non-static key in stats_request (2) To: syzbot , eperezma@redhat.com, jasowangio@gmail.com, linux-kernel@vger.kernel.org, mst@redhat.com, syzkaller-bugs@googlegroups.com, virtualization@lists.linux.dev, xuanzhuo@linux.alibaba.com References: <6a88e933.ae6ddae5.3da009.0046.GAE@google.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/22/26 02:11, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 8d3ae59288f1 Linux 7.2 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=10240679580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4c9eb8e593cf8c5c > dashboard link: https://syzkaller.appspot.com/bug?extid=13df72e0dc4be5c62215 > compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 > virtio-balloon in an RT kernel/environment, unlikely in pactice ... :) > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/cd49b631c498/disk-8d3ae592.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/05d3ad83c130/vmlinux-8d3ae592.xz > kernel image: https://storage.googleapis.com/syzbot-assets/3a2efa4a6769/bzImage-8d3ae592.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+13df72e0dc4be5c62215@syzkaller.appspotmail.com > > 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: 0 UID: 0 PID: 20235 Comm: irq/10-virtio2 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} > Tainted: [L]=SOFTLOCKUP > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 > Call Trace: > > dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 > assign_lock_key+0x133/0x150 kernel/locking/lockdep.c:984 > register_lock_class+0xcc/0x2e0 kernel/locking/lockdep.c:1299 > __lock_acquire+0xab/0x2ce0 kernel/locking/lockdep.c:5112 > lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 > rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 > spin_lock include/linux/spinlock_rt.h:45 [inline] > start_wakeup_event drivers/virtio/virtio_balloon.c:150 [inline] > stats_request+0xa5/0x1f0 drivers/virtio/virtio_balloon.c:435 I don't really understand what's happening here, Is the register_lock_class() trying to reguster a non-static key? I don't immediately see how virtio-balloon is doing something odd here, all it does is a spin_lock_irqsave(&vb->wakeup_lock, flags), that was earlier initialized with spin_lock_init(&vb->wakeup_lock), before the device was ready. -- Cheers, David