INFO: task syz.6.3934:21102 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.3934 state:D stack:25560 pid:21102 tgid:21102 ppid:19912 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5354 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6966 __schedule_loop kernel/sched/core.c:7049 [inline] schedule+0x164/0x360 kernel/sched/core.c:7064 request_wait_answer fs/fuse/dev.c:590 [inline] __fuse_request_send fs/fuse/dev.c:604 [inline] __fuse_simple_request+0x12b7/0x1db0 fs/fuse/dev.c:699 fuse_simple_request fs/fuse/fuse_i.h:1264 [inline] fuse_flush+0x66a/0x8a0 fs/fuse/file.c:500 filp_flush+0xbd/0x190 fs/open.c:1469 filp_close+0x1d/0x40 fs/open.c:1482 __range_close fs/file.c:794 [inline] __do_sys_close_range fs/file.c:855 [inline] __se_sys_close_range+0x3d4/0x900 fs/file.c:819 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: 0033:0x7f7e0ad9c819 RSP: 002b:00007ffc24de0948 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007f7e0b017da0 RCX: 00007f7e0ad9c819 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f7e0b017da0 R08: 00007f7e0b016128 R09: 0000000000000000 R10: 00000000003ffd3c R11: 0000000000000246 R12: 000000000013e84f R13: 00007f7e0b01618c R14: 000000000013e809 R15: 00007f7e0b016180 Showing all locks held in the system: 2 locks held by rcu_preempt/16: 1 lock held by khungtaskd/31: #0: ffffffff8e75d0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75d0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75d0a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5600: #0: ffff888035f410a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/13794: #0: ffffffff8fbd9580 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fbd9580 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e7633a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e7633a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 3 locks held by kworker/0:1/14179: #0: ffff8880b863ae60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff88807c650070 (&group->avgs_lock){+.+.}-{4:4}, at: psi_avgs_work+0x4d/0x160 kernel/sched/psi.c:588 3 locks held by kworker/u9:1/18348: #0: ffff888030bc7140 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3253 [inline] #0: ffff888030bc7140 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3361 #1: ffffc9000ffb7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3254 [inline] #1: ffffc9000ffb7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3361 #2: ffff888011b3cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 1 lock held by syz.1.4513/23117: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 21600 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:check_preemption_disabled+0x29/0xe0 lib/smp_processor_id.c:19 Code: 90 55 41 57 41 56 53 65 8b 05 b7 40 6b 07 65 8b 0d ac 40 6b 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d e9 09 d1 02 00 cc 9c <59> f7 c1 00 02 00 00 74 ea 65 4c 8b 3d 5e 40 6b 07 41 f6 47 2f 04 RSP: 0018:ffffc900069374f8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000202 RCX: 0000000080000000 RDX: 0000000000000000 RSI: ffffffff8df5eb80 RDI: ffffffff8c2888e0 RBP: 0000000000000000 R08: ffffffff81d60086 R09: ffffffff8e75d0a0 R10: ffffc90006937678 R11: ffffffff81b16530 R12: 0000000000000376 R13: ffffffff81d60086 R14: ffffffff8e75d0a0 R15: ffff888021b9bd00 FS: 0000000000000000(0000) GS:ffff88812543c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f76db385980 CR3: 000000000e54a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] lock_release+0xa1/0x3c0 kernel/locking/lockdep.c:5888 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] is_bpf_text_address+0x28d/0x2b0 kernel/bpf/core.c:749 kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 vfree+0x1d1/0x2f0 mm/vmalloc.c:3472 kcov_put kernel/kcov.c:442 [inline] kcov_close+0x28/0x50 kernel/kcov.c:543 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x22c0 kernel/exit.c:974 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116 get_signal+0x1284/0x1330 kernel/signal.c:3036 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbac255d04e Code: Unable to access opcode bytes at 0x7fbac255d024. RSP: 002b:00007ffed1b38c08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 000055555903a500 RCX: 00007fbac255d04e RDX: 00007ffed1b38c60 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffed1b38ccc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000001388 R13: 00000000000927c0 R14: 0000000000163394 R15: 00007ffed1b38d20