INFO: task syz.2.1379:13445 blocked for more than 144 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1379 state:D stack:27064 pid:13445 tgid:13445 ppid:11026 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 __flush_work+0x9b9/0xbc0 kernel/workqueue.c:4331 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4451 hci_cmd_sync_clear+0x30/0x230 net/bluetooth/hci_sync.c:655 hci_unregister_dev+0x194/0x5b0 net/bluetooth/hci_core.c:2711 vhci_release+0x152/0x1a0 drivers/bluetooth/hci_vhci.c:690 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x694/0x22f0 kernel/exit.c:971 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa20fbc2005 RSP: 002b:00007fa20ddb3f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fa20fde6180 RCX: 00007fa20fbc2005 RDX: 00007fa20ddb3fc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fa20fc13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007fa20fde6218 R14: 00007fa20fde6180 R15: 00007ffcbd62e868 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:302 [inline] #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:5/625: #0: ffff88813fe29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc900032f7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 3 locks held by kworker/u9:1/5143: #0: ffff88801ffbe148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc9000ee67c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffff88802d3b0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 2 locks held by getty/5577: #0: ffff88814e35d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:18/6173: #0: ffff88813fe29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc90005667c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 2 locks held by dhcpcd/9050: #0: ffff8880771fa488 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff8880771fa488 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x89/0x250 net/socket.c:665 #1: ffffffff8e1448f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e1448f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:961 1 lock held by syz-executor/14701: #0: ffffffff8e1448f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8e1448f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2b1/0x6e0 kernel/rcu/tree_exp.h:961 2 locks held by kworker/0:3/15088: #0: ffff8880b863ab98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 1 lock held by sed/15305: #0: ffff8880b873ab98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:375 [inline] watchdog+0xe88/0xee0 kernel/hung_task.c:588 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 15007 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:mark_usage kernel/locking/lockdep.c:4620 [inline] RIP: 0010:__lock_acquire+0x5ee/0x2cf0 kernel/locking/lockdep.c:5191 Code: 3b 9e 00 0b 00 00 0f 8c 0b ff ff ff 44 89 e0 38 04 24 76 16 e8 03 8e ed 02 85 c0 74 0d 83 3d 7c 79 04 0e 00 0f 84 0a 08 00 00 <83> 7c 24 10 00 0f 84 a8 00 00 00 41 8b 45 20 66 85 c0 0f 88 8c 00 RSP: 0018:ffffc90000007710 EFLAGS: 00000093 RAX: 0000000000000003 RBX: ffff88805916c820 RCX: 0000000000000003 RDX: 0000000000000003 RSI: 0000000000002000 RDI: 0000000000000000 RBP: ffff88805916c800 R08: ffffffff8173fd85 R09: ffffffff8e13f2e0 R10: ffffc90000007a18 R11: ffffffff81acaae0 R12: 0000000000000003 R13: ffff88805916c800 R14: ffff88805916bc80 R15: 0000000000000003 FS: 0000555569b41500(0000) GS:ffff888125c0c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564726720660 CR3: 000000002b684000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:302 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1166 [inline] unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6674 [inline] kfree+0x1c0/0x660 mm/slub.c:6882 slab_free_after_rcu_debug+0x5d/0x260 mm/slub.c:6720 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7bd/0x1060 kernel/rcu/tree.c:2869 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:626 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 sock_orphan include/net/sock.h:2120 [inline] unix_release_sock+0x463/0xc70 net/unix/af_unix.c:678 unix_release+0x92/0xd0 net/unix/af_unix.c:1184 __sock_release+0xb9/0x250 net/socket.c:666 sock_close+0x1c/0x30 net/socket.c:1470 __fput+0x44c/0xa70 fs/file_table.c:468 fput_close_sync+0x113/0x220 fs/file_table.c:573 __do_sys_close fs/open.c:1534 [inline] __se_sys_close fs/open.c:1519 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1519 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd9f918eea7 Code: 44 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb bc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007fff6a45e078 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fd9f918eea7 RDX: 0000000000000000 RSI: 0000000000008933 RDI: 0000000000000005 RBP: 00007fff6a45e080 R08: 000000000000000a R09: 00007fff6a45e3a0 R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000003 R13: 00007fd9f9f14620 R14: 0000000000000006 R15: 0000000000000000