INFO: task syz.7.1035:10603 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.1035 state:D stack:27520 pid:10603 tgid:10597 ppid:9437 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820 sync_bdevs+0x153/0x480 block/bdev.c:1296 ksys_sync+0xb0/0xf0 fs/sync.c:105 __do_sys_sync+0xe/0x20 fs/sync.c:111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f943499cdd9 RSP: 002b:00007f9435864028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f9434c16090 RCX: 00007f943499cdd9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f9434c16090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9434c16128 R14: 00007f9434c16090 R15: 00007ffed9eb5a38 Showing all locks held in the system: 3 locks held by kworker/0:1/10: 1 lock held by rcu_exp_gp_kthr/18: 3 locks held by kworker/1:1/29: #0: ffff88813fe5b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc90000a47d08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffffffff8e7f1028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by khungtaskd/31: #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5370: #0: ffff88803352c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:6/5734: #0: ffff88813fe5b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline] #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2d69/0x6820 kernel/sched/core.c:7183 #2: ffff88805d48b250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b8/0x63b0 drivers/net/netdevsim/fib.c:1490 1 lock held by udevd/6347: #0: ffff888027e12350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:953 1 lock held by syz.7.1035/10603: #0: ffff888027e12350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1296 2 locks held by syz-executor/11131: #0: ffff8880841d0ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 #1: ffff8880841d00b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356 4 locks held by syz-executor/13065: #0: ffff88802b150ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 #1: ffff88802b1500b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356 #2: ffffffff90891800 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff90891800 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2650 #3: ffff8880299712f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x95/0x710 net/bluetooth/l2cap_core.c:1777 1 lock held by syz.3.1458/13493: #0: ffffffff8e7f1028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 1 lock held by cmp/13512: ============================================= 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 04/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13441 Comm: vhost-13440 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1108 [inline] RIP: 0010:debug_check_no_obj_freed+0x210/0x630 lib/debugobjects.c:1146 Code: 00 00 48 89 c2 31 f6 49 89 df 4c 89 74 24 28 48 c1 ea 03 89 f3 42 80 3c 22 00 0f 85 dd 00 00 00 48 8d 78 18 83 c3 01 4c 8b 30 <48> 89 fa 48 c1 ea 03 42 80 3c 22 00 0f 85 27 03 00 00 48 8b 50 18 RSP: 0018:ffffc90003d77980 EFLAGS: 00000006 RAX: ffff888021375118 RBX: 0000000000000005 RCX: ffffffff81e4c478 RDX: 1ffff1100426ea23 RSI: 0000000000000000 RDI: ffff888021375130 RBP: ffffc90003d77ab0 R08: 0000000000000001 R09: fffff520007aef1e R10: 0000000000000003 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffc90005699000 R14: 0000000000000000 R15: ffffc90005a99000 FS: 0000000000000000(0000) GS:ffff888124376000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe00f25368 CR3: 000000007a0c3000 CR4: 00000000003526f0 Call Trace: remove_vm_area+0x1b0/0x390 mm/vmalloc.c:3330 vfree mm/vmalloc.c:3453 [inline] vfree+0x6f/0x8d0 mm/vmalloc.c:3436 kcov_put kernel/kcov.c:442 [inline] kcov_put kernel/kcov.c:438 [inline] kcov_close+0x34/0x60 kernel/kcov.c:543 __fput+0x3ff/0xb50 fs/file_table.c:510 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8d2/0x2a60 kernel/exit.c:975 vhost_task_fn+0x31a/0x430 kernel/vhost_task.c:67 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245