From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp153-171.sina.com.cn (smtp153-171.sina.com.cn [61.135.153.171]) (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 788682D5932 for ; Thu, 21 May 2026 01:53:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=61.135.153.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779328415; cv=none; b=fluk/0xfw4gbwPo9AfLtcnwbyODj+1dgqOCV+UlB968f6v3bns0TUQmpq8UuMwXMyxPDd44Kmx7knc8r8iG1vbGL5FomRrBJYPoJOi3Z5EaME2KtBPQYMdNRoGJooUTwNyZc67oCS6oTug4ksTLrTrEK7sej9l4kDYw88dqELyY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779328415; c=relaxed/simple; bh=hA3rIC4dMr+fpMGONwGjD+wyfv5+6rCI2l2lLq+fKV0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; 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<6a0de9e2.050a0220.18b3cb.000d.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit > Date: Wed, 20 May 2026 10:05:38 -0700 [thread overview] > 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 > Deadlock if the timer thread is preempted timer thread tasklet_sync_callback.cb_lock // preempted &dev->event_lock do softirq acquire tasklet_sync_callback.cb_lock acquire &dev->event_lock > -> #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 >