INFO: task syz.6.595:8802 blocked for more than 143 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.595 state:D stack:26008 pid:8802 tgid:8802 ppid:6136 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 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:4277 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4397 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+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd2fefc2005 RSP: 002b:00007fd2ffe64f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fd2ff1e5fa0 RCX: 00007fd2fefc2005 RDX: 00007fd2ffe64fc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fd2ff013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007fd2ff1e6038 R14: 00007fd2ff1e5fa0 R15: 00007ffe0372be38 Showing all locks held in the system: 2 locks held by kworker/u8:1/13: #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90000127bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000127bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 1 lock held by khungtaskd/32: #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/37: 2 locks held by getty/5576: #0: ffff88803459d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 2 locks held by kworker/0:3/5808: 3 locks held by kworker/u9:4/5833: #0: ffff888063d5a148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888063d5a148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000403fbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000403fbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff88802faa0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 3 locks held by kworker/u8:15/6023: 4 locks held by syz-executor/9629: 4 locks held by syz-executor/10467: 1 lock held by syz-executor/10617: 5 locks held by syz.1.1112/11012: 2 locks held by syz.0.1109/11014: #0: ffff88802f1460e0 (&type->s_umount_key#61/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xaa0 fs/super.c:344 #1: ffffffff8e00dac8 (lock#5){+.+.}-{4:4}, at: __lru_add_drain_all+0x6b/0x5e0 mm/swap.c:840 4 locks held by syz.4.1113/11019: 1 lock held by syz-executor/11021: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 32 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:160 [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:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 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: 11019 Comm: syz.4.1113 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:__might_sleep+0xf/0xf0 kernel/sched/core.c:8743 Code: 07 ea 94 00 e9 2f ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 50 <49> bf 00 00 00 00 00 fc ff df 65 48 8b 1c 25 08 10 80 92 4c 8d 73 RSP: 0018:ffffc9000bb074e0 EFLAGS: 00000202 RAX: ffffc9000bb07620 RBX: ffffc9000bb07600 RCX: 0000000000000000 RDX: 0000000000000028 RSI: 000000000000024f RDI: ffffffff8b6b19c0 RBP: ffffc9000bb076d0 R08: ffffc9000bb07647 R09: ffffc9000bb07620 R10: dffffc0000000000 R11: fffff52001760ec9 R12: ffff888031d3d450 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f8cb7e8e6c0(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2bff05 CR3: 000000002968f000 CR4: 0000000000350ef0 Call Trace: __mutex_lock_common kernel/locking/mutex.c:591 [inline] __mutex_lock+0x109/0x1350 kernel/locking/mutex.c:776 __unix_dgram_recvmsg+0x1e1/0xd60 net/unix/af_unix.c:2573 sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1078 ____sys_recvmsg+0x3aa/0x460 net/socket.c:2810 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2854 do_recvmmsg+0x307/0x770 net/socket.c:2949 __sys_recvmmsg net/socket.c:3023 [inline] __do_sys_recvmmsg net/socket.c:3046 [inline] __se_sys_recvmmsg net/socket.c:3039 [inline] __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3039 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: 0033:0x7f8cb6f8f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8cb7e8e038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f8cb71e6090 RCX: 00007f8cb6f8f749 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007f8cb7013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8cb71e6128 R14: 00007f8cb71e6090 R15: 00007ffcd191f208