INFO: task syz-executor:21584 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22528 pid:21584 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f559e9f11ff RSP: 002b:00007ffff2de9630 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f559e9f11ff RDX: 0000000000000001 RSI: 00007ffff2de9680 RDI: 0000000000000005 RBP: 00007f559ea782cb R08: 0000000000000000 R09: 00007ffff2de9487 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffff2de9680 R14: 00007f559f777620 R15: 0000000000000003 INFO: task syz-executor:21699 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22368 pid:21699 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f1e5b5211ff RSP: 002b:00007ffe79432130 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f1e5b5211ff RDX: 0000000000000001 RSI: 00007ffe79432180 RDI: 0000000000000005 RBP: 00007f1e5b5a82cb R08: 0000000000000000 R09: 00007ffe79431f87 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffe79432180 R14: 00007f1e5c2a7620 R15: 0000000000000003 Showing all locks held in the system: 3 locks held by kworker/0:0/7: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90000cc7d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c1210f0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043 1 lock held by ksoftirqd/0/14: 1 lock held by khungtaskd/27: #0: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3943: #0: ffff88802b68e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 2 locks held by kworker/1:9/4296: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003f6fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 3 locks held by kworker/0:7/4330: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002f5fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c1210f0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043 3 locks held by kworker/1:11/5953: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000344fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #2: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 3 locks held by kworker/1:14/14536: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003d6fd00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff888062e70400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xb40 drivers/net/netdevsim/dev.c:757 3 locks held by kworker/1:23/14543: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90003dbfd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c1210f0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043 7 locks held by kworker/u4:18/14629: #0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002effd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589 #3: ffffffff8d25e048 (devlink_mutex){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0x97/0x300 net/core/devlink.c:11534 #4: ffff88802a848658 (&nsim_bus_dev->nsim_bus_reload_lock){+.+.}-{3:3}, at: nsim_dev_reload_down+0x57/0x160 drivers/net/netdevsim/dev.c:870 #5: ffff888062e70400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline] #5: ffff888062e70400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x115/0x240 drivers/net/netdevsim/dev.c:1561 #6: ffffffff8c1210f0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043 3 locks held by kworker/u4:51/14687: 6 locks held by syz-executor/20969: #0: ffff88807ec96460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff888041d39888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffff8880221990f0 (kn->active#296){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288 #3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344 #4: ffff888075d84178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #4: ffff888075d84178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline] #4: ffff888075d84178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb0/0x750 drivers/base/dd.c:1259 #5: ffffffff8d25e048 (devlink_mutex){+.+.}-{3:3}, at: devlink_unregister+0x92/0x1d0 net/core/devlink.c:8984 4 locks held by syz-executor/21584: #0: ffff88807ec96460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff88805e8b9088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffff8880221990f0 (kn->active#296){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288 #3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344 4 locks held by syz-executor/21699: #0: ffff88807ec96460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff888041d38088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffff8880221990f0 (kn->active#296){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288 #3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344 4 locks held by syz-executor/22336: #0: ffff88807ec96460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff8880737fac88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffff8880221990f0 (kn->active#296){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288 #3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344 4 locks held by syz-executor/22481: #0: ffff88807ec96460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff88803125c488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffff8880221990f0 (kn->active#296){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288 #3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344 4 locks held by syz-executor/23088: #0: ffff88807ec96460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff88803470a088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffff8880221990f0 (kn->active#296){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288 #3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344 4 locks held by syz-executor/23152: #0: ffff88807ec96460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590 #1: ffff888041d9a488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287 #2: ffff8880221990f0 (kn->active#296){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288 #3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344 3 locks held by sed/23688: #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffff8880b9027888 ( &per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4d6/0x810 kernel/sched/psi.c:891 #2: ffff88802bc9a738 (&sig->wait_chldexit){....}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:137 [inline] #2: ffff88802bc9a738 (&sig->wait_chldexit){....}-{2:2}, at: __wake_up_sync_key+0xf0/0x180 kernel/sched/wait.c:205 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 50 d3 f1 0b 48 89 de 5b e9 57 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d a4 a3 8a 7e 65 8b 15 a5 a3 8a 7e 81 e2 00 RSP: 0018:ffffc90000d37820 EFLAGS: 00000246 RAX: ffffffff888bf332 RBX: ffff88805b880640 RCX: ffff88813fea9dc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ad33a6 R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: ffff8880674ca0c4 R13: dffffc0000000000 R14: ffff88807ddb0000 R15: ffff8880674ca000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563d9c118950 CR3: 000000007e758000 CR4: 00000000003506f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: l3mdev_l3_rcv include/net/l3mdev.h:171 [inline] l3mdev_ip6_rcv include/net/l3mdev.h:190 [inline] ip6_rcv_finish+0x19b/0x240 net/ipv6/ip6_input.c:74 NF_HOOK+0x2d6/0x360 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5525 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5639 process_backlog+0x364/0x780 net/core/dev.c:6516 __napi_poll+0xc0/0x430 net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x4a8/0x9c0 net/core/dev.c:7232 handle_softirqs+0x328/0x820 kernel/softirq.c:576 run_ksoftirqd+0x98/0xf0 kernel/softirq.c:943 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287