From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f80.google.com (mail-oo1-f80.google.com [209.85.161.80]) (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 0262D3F5BE1 for ; Wed, 20 May 2026 17:05:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.80 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779296741; cv=none; b=oxs7nWNQt6sGS9SApiBtkHi/i4SJp3yB4TJPqfwjgPm/i7FQPNQTduPBo+L7c3jUPSHn1bxiPwqRyDPCZzUHYP8sydm7zBG9h+AgModq4wCkw4vSLlFf/PkEmXRHgoJoQdCcJynT021oxebeMQZzO0bh+llrD5vJnP4UjBXqajg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779296741; c=relaxed/simple; bh=UmRNDaGlgfAIqIbxHwng1eAB1GzkWWa7M1ZnYWApj5I=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=gcHKQKHW3+SD0BCZIX+D2SiGmwgQG0m8qqnrYeiKn6Z7KRqBOAiX4jEYkucxts2ghy5zLD9f54RWsmFDWCzNtQTeXxFvGZ+MCCsLRGCncdDqG8Uq3ndv+y5iIDpUrx8pssBhjKsjZ4mXQEILNeNG96l89UEMMDjEWIeGqmsPn5o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.161.80 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oo1-f80.google.com with SMTP id 006d021491bc7-6961163ad6aso13540468eaf.1 for ; Wed, 20 May 2026 10:05:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779296739; x=1779901539; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=6DtNsBOrYpeB2rnZC0wNTP4qsMtdriuLddaqFV/gRfw=; b=L6MahF22nYeaKgS8BPKO18nNIWnXavpJHZFR7UHpvUO2z+kpEP4FTaEITvWjK1G+NU oNH7GZF2yJGyTXydFmQGY6/O4jFcaMyOKZrhEDiCUPG7k2v6dkRezqX21LF/2z77vXvP UX9RG0Mqi9iIOHi682PkG1gEytvmwMEAJ1wmZquDozYujvM3nn3iAQ9VdCTY8tz3+Q16 JI/S9LnNgEISs4fNMvvZhiT7nSu6heTf9Dm9s+NClScKsO+I4RXh/7c5gS9sL2w+VRa5 2oFydn2IfiI1RosqATOJ/Oo6HCwA6Ldi27qsAHqlhUDkI6dQXkj5ejsmGcAJ3DM1Mzn8 cR3A== X-Forwarded-Encrypted: i=1; AFNElJ/sXzg/rSlcicgMcnO/gdKeERcNdNCY0apk2I71Yxdo4t3yJaGkiNdEpxZwOYxGvg3nuua0aY+XxuJhGg==@vger.kernel.org X-Gm-Message-State: AOJu0YxW9eT6/RhFk+tLiMCX2rsPxjcvLtCNC4RxCuWQ4XXtHW8hxjyS 0rTbnM9kAZC0pFz/2ujty7fpG6DrUBPZXGPc1etm6pwlgaAkqtj9XNKtcbYbHhsa7TOiY4K9bRB EFdm1VSkvS/WiNN5GLWy31AR/AOXJAqKP4QZXUjV6slG7GfXAwebUZPhWckY= Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:f07:b0:67e:16b4:aa0d with SMTP id 006d021491bc7-69c9437c154mr14159899eaf.30.1779296738894; Wed, 20 May 2026 10:05:38 -0700 (PDT) Date: Wed, 20 May 2026 10:05:38 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a0de9e2.050a0220.18b3cb.000d.GAE@google.com> Subject: [syzbot] [input?] possible deadlock in tasklet_action_common (2) From: syzbot To: dmitry.torokhov@gmail.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: e98d21c170b0 Add linux-next specific files for 20260508 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1354bfce580000 kernel config: https://syzkaller.appspot.com/x/.config?x=59b98218d9b2edf4 dashboard link: https://syzkaller.appspot.com/bug?extid=b5d7ab56d43de3fd5aac compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/66f2a00ee290/disk-e98d21c1.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/6b982257ce9e/vmlinux-e98d21c1.xz kernel image: https://storage.googleapis.com/syzbot-assets/a73fbea43e1a/bzImage-e98d21c1.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b5d7ab56d43de3fd5aac@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.2.4328/32663 is trying to acquire lock: ffff8880b8724168 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] ffff8880b8724168 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: tasklet_lock_callback kernel/softirq.c:881 [inline] ffff8880b8724168 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: tasklet_action_common+0xc5/0x610 kernel/softirq.c:931 but task is already holding lock: ffff888058598270 (&dev->event_lock#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] ffff888058598270 (&dev->event_lock#2){+.+.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:619 [inline] ffff888058598270 (&dev->event_lock#2){+.+.}-{3:3}, at: input_inject_event+0xa4/0x320 drivers/input/input.c:419 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&dev->event_lock#2){+.+.}-{3:3}: rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:45 [inline] class_spinlock_irqsave_constructor include/linux/spinlock.h:619 [inline] input_inject_event+0xa4/0x320 drivers/input/input.c:419 led_trigger_event+0x13b/0x220 drivers/leds/led-triggers.c:420 kbd_propagate_led_state drivers/tty/vt/keyboard.c:1118 [inline] kbd_bh+0x1b4/0x2c0 drivers/tty/vt/keyboard.c:1297 tasklet_action_common+0x31c/0x610 kernel/softirq.c:942 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1155 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #0 (tasklet_sync_callback.cb_lock){+...}-{3:3}: check_prev_add kernel/locking/lockdep.c:3167 [inline] check_prevs_add kernel/locking/lockdep.c:3286 [inline] validate_chain kernel/locking/lockdep.c:3910 [inline] __lock_acquire+0x15a5/0x2d10 kernel/locking/lockdep.c:5239 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5870 rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:45 [inline] tasklet_lock_callback kernel/softirq.c:881 [inline] tasklet_action_common+0xc5/0x610 kernel/softirq.c:931 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x1aa/0x7d0 net/core/skbuff.c:697 alloc_skb include/linux/skbuff.h:1381 [inline] hidp_send_message+0xb5/0x230 net/bluetooth/hidp/core.c:111 hidp_send_intr_message net/bluetooth/hidp/core.c:143 [inline] hidp_input_event+0x2a4/0x380 net/bluetooth/hidp/core.c:175 input_event_dispose+0x80/0x6b0 drivers/input/input.c:322 input_inject_event+0x1d7/0x320 drivers/input/input.c:424 kbd_led_trigger_activate+0xbc/0x100 drivers/tty/vt/keyboard.c:1074 led_trigger_set+0x53b/0x960 drivers/leds/led-triggers.c:220 led_match_default_trigger drivers/leds/led-triggers.c:277 [inline] led_trigger_set_default+0x266/0x2a0 drivers/leds/led-triggers.c:300 led_classdev_register_ext+0x787/0x9c0 drivers/leds/led-class.c:581 led_classdev_register include/linux/leds.h:274 [inline] input_leds_connect+0x517/0x790 drivers/input/input-leds.c:145 input_attach_handler drivers/input/input.c:1011 [inline] input_register_device+0xce0/0x1140 drivers/input/input.c:2395 hidp_session_dev_add net/bluetooth/hidp/core.c:861 [inline] hidp_session_probe+0x1a5/0x8a0 net/bluetooth/hidp/core.c:1139 l2cap_register_user+0xc2/0x1d0 net/bluetooth/l2cap_core.c:1725 hidp_connection_add+0x158b/0x1a20 net/bluetooth/hidp/core.c:1411 do_hidp_sock_ioctl net/bluetooth/hidp/sock.c:81 [inline] hidp_sock_ioctl+0x403/0x650 net/bluetooth/hidp/sock.c:128 sock_do_ioctl+0x101/0x320 net/socket.c:1328 sock_ioctl+0x5c9/0x7f0 net/socket.c:1449 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dev->event_lock#2); lock(tasklet_sync_callback.cb_lock); lock(&dev->event_lock#2); lock(tasklet_sync_callback.cb_lock); *** DEADLOCK *** 10 locks held by syz.2.4328/32663: #0: ffff88805ebb3370 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_register_user+0x35/0x1d0 net/bluetooth/l2cap_core.c:1712 #1: ffffffff8f73d960 (hidp_session_sem){++++}-{4:4}, at: hidp_session_probe+0x98/0x8a0 net/bluetooth/hidp/core.c:1129 #2: ffffffff8f006e58 (input_mutex){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline] #2: ffffffff8f006e58 (input_mutex){+.+.}-{4:4}, at: input_register_device+0xa56/0x1140 drivers/input/input.c:2391 #3: ffff8880125ea860 (&led_cdev->led_access){+.+.}-{4:4}, at: led_classdev_register_ext+0x484/0x9c0 drivers/leds/led-class.c:539 #4: ffffffff8e9c4400 (triggers_list_lock){++++}-{4:4}, at: led_trigger_set_default+0x77/0x2a0 drivers/leds/led-triggers.c:297 #5: ffff8880125ea788 (&led_cdev->trigger_lock){+.+.}-{4:4}, at: led_trigger_set_default+0x87/0x2a0 drivers/leds/led-triggers.c:298 #6: ffff888058598270 (&dev->event_lock#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #6: ffff888058598270 (&dev->event_lock#2){+.+.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:619 [inline] #6: ffff888058598270 (&dev->event_lock#2){+.+.}-{3:3}, at: input_inject_event+0xa4/0x320 drivers/input/input.c:419 #7: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #7: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #7: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #7: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #8: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #8: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #8: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline] #8: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: input_inject_event+0xb0/0x320 drivers/input/input.c:420 #9: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 stack backtrace: CPU: 1 UID: 0 PID: 32663 Comm: syz.2.4328 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2045 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3167 [inline] check_prevs_add kernel/locking/lockdep.c:3286 [inline] validate_chain kernel/locking/lockdep.c:3910 [inline] __lock_acquire+0x15a5/0x2d10 kernel/locking/lockdep.c:5239 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5870 rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:45 [inline] tasklet_lock_callback kernel/softirq.c:881 [inline] tasklet_action_common+0xc5/0x610 kernel/softirq.c:931 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x1aa/0x7d0 net/core/skbuff.c:697 alloc_skb include/linux/skbuff.h:1381 [inline] hidp_send_message+0xb5/0x230 net/bluetooth/hidp/core.c:111 hidp_send_intr_message net/bluetooth/hidp/core.c:143 [inline] hidp_input_event+0x2a4/0x380 net/bluetooth/hidp/core.c:175 input_event_dispose+0x80/0x6b0 drivers/input/input.c:322 input_inject_event+0x1d7/0x320 drivers/input/input.c:424 kbd_led_trigger_activate+0xbc/0x100 drivers/tty/vt/keyboard.c:1074 led_trigger_set+0x53b/0x960 drivers/leds/led-triggers.c:220 led_match_default_trigger drivers/leds/led-triggers.c:277 [inline] led_trigger_set_default+0x266/0x2a0 drivers/leds/led-triggers.c:300 led_classdev_register_ext+0x787/0x9c0 drivers/leds/led-class.c:581 led_classdev_register include/linux/leds.h:274 [inline] input_leds_connect+0x517/0x790 drivers/input/input-leds.c:145 input_attach_handler drivers/input/input.c:1011 [inline] input_register_device+0xce0/0x1140 drivers/input/input.c:2395 hidp_session_dev_add net/bluetooth/hidp/core.c:861 [inline] hidp_session_probe+0x1a5/0x8a0 net/bluetooth/hidp/core.c:1139 l2cap_register_user+0xc2/0x1d0 net/bluetooth/l2cap_core.c:1725 hidp_connection_add+0x158b/0x1a20 net/bluetooth/hidp/core.c:1411 do_hidp_sock_ioctl net/bluetooth/hidp/sock.c:81 [inline] hidp_sock_ioctl+0x403/0x650 net/bluetooth/hidp/sock.c:128 sock_do_ioctl+0x101/0x320 net/socket.c:1328 sock_ioctl+0x5c9/0x7f0 net/socket.c:1449 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcb5e6cce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcb5c905028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcb5e946090 RCX: 00007fcb5e6cce59 RDX: 00002000000000c0 RSI: 00000000400448c8 RDI: 0000000000000009 RBP: 00007fcb5e762d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcb5e946128 R14: 00007fcb5e946090 R15: 00007ffddb8adae8 --- 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