INFO: task syz.1.3010:13413 blocked for more than 143 seconds. Not tainted 6.1.148-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3010 state:D stack:23552 pid:13413 ppid:13100 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 perf_pending_task_sync kernel/events/core.c:5031 [inline] _free_event+0x171/0x10a0 kernel/events/core.c:5037 put_event kernel/events/core.c:5162 [inline] perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5287 perf_release+0x37/0x40 kernel/events/core.c:5297 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 get_signal+0x11a6/0x1350 kernel/signal.c:2648 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb5d8f8ebe9 RSP: 002b:00007fb5d9eeafe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007fb5d91b5fa0 RCX: 00007fb5d8f8ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000042000000 RBP: 00007fb5d9011e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fb5d91b6038 R14: 00007fb5d91b5fa0 R15: 00007ffd2e976e38 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b770 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bf90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2ade0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2ade0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2ade0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4029: #0: ffff88814d012098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 2 locks held by kworker/1:11/9228: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90006107d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 4 locks held by kworker/u4:7/10717: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000e2a7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd33e10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: xfrmi_exit_batch_net+0xb0/0x350 net/xfrm/xfrm_interface_core.c:951 2 locks held by syz-executor/13882: 1 lock held by syz.9.3269/14402: #0: ffffffff8cb30ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #0: ffffffff8cb30ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 1 lock held by syz.8.3272/14437: 2 locks held by syz.0.3286/14477: #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492 #1: ffffffff8cb30ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #1: ffffffff8cb30ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 2 locks held by syz.2.3293/14493: #0: ffffffff8dd33e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504 #1: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x7d/0x210 net/ipv4/nexthop.c:3606 1 lock held by syz.2.3293/14494: #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x567/0xea0 net/core/dev_ioctl.c:587 1 lock held by syz.2.3293/14495: #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104 1 lock held by syz.2.3293/14496: #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: tun_set_queue drivers/net/tun.c:2975 [inline] #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x361/0x1e10 drivers/net/tun.c:3097 1 lock held by syz.2.3293/14497: #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x567/0xea0 net/core/dev_ioctl.c:587 1 lock held by syz.2.3293/14503: #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x567/0xea0 net/core/dev_ioctl.c:587 1 lock held by syz-executor/14500: #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 1 lock held by syz.1.3295/14506: #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104 1 lock held by syz.1.3295/14507: #0: ffffffff8dd40aa8 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x567/0xea0 net/core/dev_ioctl.c:587 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 46 Comm: kworker/u4:3 Not tainted 6.1.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xb1/0x100 kernel/locking/spinlock.c:194 Code: 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e8 86 3c 37 f7 65 8b 05 d7 05 e2 75 <85> c0 74 3c 48 c7 04 24 0e 36 e0 45 4b c7 04 27 00 00 00 00 65 48 RSP: 0018:ffffc90000b76d60 EFLAGS: 00000297 RAX: 0000000080000000 RBX: 0000000000000a06 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff8a8c0420 RDI: 00000000ffffffff RBP: ffffc90000b76df0 R08: dffffc0000000000 R09: fffffbfff215bc5f R10: fffffbfff215bc5f R11: 1ffffffff215bc5e R12: dffffc0000000000 R13: 1ffff9200016edcc R14: ffff888025751070 R15: 1ffff9200016edac FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559190df1fb0 CR3: 000000007feeb000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] virtscsi_add_cmd+0x55d/0x620 drivers/scsi/virtio_scsi.c:497 virtscsi_queuecommand+0x6d7/0xba0 drivers/scsi/virtio_scsi.c:590 scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1537 [inline] scsi_queue_rq+0x1e23/0x2f10 drivers/scsi/scsi_lib.c:1774 blk_mq_dispatch_rq_list+0x986/0x21a0 block/blk-mq.c:2086 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:172 [inline] blk_mq_do_dispatch_sched+0x874/0xdf0 block/blk-mq-sched.c:186 __blk_mq_sched_dispatch_requests+0x311/0x3f0 block/blk-mq-sched.c:-1 blk_mq_sched_dispatch_requests+0xf7/0x1b0 block/blk-mq-sched.c:338 __blk_mq_run_hw_queue+0x233/0x2f0 block/blk-mq.c:2205 blk_mq_sched_insert_requests+0x5c5/0x890 block/blk-mq-sched.c:492 blk_mq_dispatch_plug_list block/blk-mq.c:2796 [inline] blk_mq_flush_plug_list+0xc38/0xd40 block/blk-mq.c:2845 __blk_flush_plug+0x3c6/0x440 block/blk-core.c:1163 blk_finish_plug+0x59/0x80 block/blk-core.c:1187 wb_writeback+0xc84/0xd00 fs/fs-writeback.c:2111 wb_check_old_data_flush fs/fs-writeback.c:2179 [inline] wb_do_writeback fs/fs-writeback.c:2232 [inline] wb_workfn+0xb66/0xec0 fs/fs-writeback.c:2260 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295