INFO: task syz.0.3683:667 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.3683 state:D stack:27640 pid:667 tgid:666 ppid:23038 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 bdev_open+0xa2/0xe40 block/bdev.c:945 bdev_file_open_by_dev block/bdev.c:1059 [inline] bdev_file_open_by_dev+0x182/0x210 block/bdev.c:1034 setup_bdev_super+0x78/0x730 fs/super.c:1610 get_tree_bdev_flags+0x363/0x620 fs/super.c:1690 vfs_get_tree+0x8e/0x340 fs/super.c:1815 do_new_mount fs/namespace.c:3808 [inline] path_mount+0x1513/0x2000 fs/namespace.c:4123 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount fs/namespace.c:4324 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff4ded8ebe9 RSP: 002b:00007ff4dfc30038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ff4defb5fa0 RCX: 00007ff4ded8ebe9 RDX: 0000200000000040 RSI: 0000200000004a00 RDI: 00002000000003c0 RBP: 00007ff4dee11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000008007 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff4defb6038 R14: 00007ff4defb5fa0 R15: 00007ffcdcdc4a08 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff88801f7e6148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000117d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 4 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/36: 3 locks held by kworker/u8:6/3555: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000ca1fd10 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 2 locks held by getty/5603: #0: ffff88803628c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 5 locks held by kworker/1:6/5962: #0: ffff8881442b3548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000477fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff888145b7a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff888145b7a198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff888145b7d518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline] #3: ffff888145b7d518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline] #3: ffff888145b7d518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #3: ffff888145b7d518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #3: ffff888145b7d518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2981/0x4fe0 drivers/usb/core/hub.c:5952 #4: ffff888145b98468 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #4: ffff888145b98468 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #4: ffff888145b98468 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #4: ffff888145b98468 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x29aa/0x4fe0 drivers/usb/core/hub.c:5952 3 locks held by kworker/u8:32/17343: #0: ffff88814d3f8948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9001f047d10 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x120/0x14e0 net/ipv6/addrconf.c:4194 4 locks held by kworker/0:9/20297: #0: ffff88814529b948 ((wq_completion)infiniband){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000d9c7d10 ((work_completion)(&work->work)#3){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff8880250f1290 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0xf1/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:61 #3: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x117/0xb50 drivers/infiniband/core/verbs.c:1995 3 locks held by kworker/0:14/20306: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000ebbfd10 ((work_completion)(&smcibdev->port_event_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff8880250f1290 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0xf1/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:61 3 locks held by kworker/1:0/20310: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000d88fd10 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8e5cc7b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by udevd/23026: #0: ffff8881437fa358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 2 locks held by syz.0.3683/667: #0: ffff8880328280e0 (&type->s_umount_key#105/1){+.+.}-{4:4}, at: alloc_super+0x235/0xbd0 fs/super.c:345 #1: ffff8881437fa358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xa2/0xe40 block/bdev.c:945 1 lock held by syz.7.3790/2982: #0: ffff8880448f2428 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x342/0xa30 fs/splice.c:1105 2 locks held by syz.5.3993/5939: #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433 #1: ffffffff8e5cc7b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 4 locks held by syz-executor/7272: #0: ffff88808a0dcdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff88808a0dc0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5282 #2: ffffffff905eb368 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2094 [inline] #2: ffffffff905eb368 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2575 #3: ffff888079459338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1762 1 lock held by syz.8.4123/7826: #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433 6 locks held by syz.9.4128/7885: #0: ffffffff9b19d9d8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_msg+0x169/0x6e0 drivers/infiniband/core/netlink.c:164 #1: ffffffff8ffb1df0 (link_ops_rwsem){++++}-{4:4}, at: nldev_newlink+0x2e6/0x680 drivers/infiniband/core/nldev.c:1787 #2: ffffffff8ff9dbd0 (devices_rwsem){++++}-{4:4}, at: enable_device_and_get+0x103/0x3f0 drivers/infiniband/core/device.c:1358 #3: ffffffff8ff9d950 (rdma_nets_rwsem){++++}-{4:4}, at: add_compat_devs drivers/infiniband/core/device.c:1061 [inline] #3: ffffffff8ff9d950 (rdma_nets_rwsem){++++}-{4:4}, at: enable_device_and_get+0x2cb/0x3f0 drivers/infiniband/core/device.c:1374 #4: ffff8880250f0f98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0x112/0x7d0 drivers/infiniband/core/device.c:979 #5: ffff8880250f1290 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0xf1/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:61 1 lock held by syz.5.4129/7888: #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433 1 lock held by syz.1.4130/7896: #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90383308 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3433 ============================================= 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 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 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: 17348 Comm: kworker/u8:36 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:412 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 db 5e 95 f5 cc RSP: 0018:ffffc9000c34f670 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc9000c350000 RDX: ffffc9000c34fa01 RSI: ffffc9000c34faf0 RDI: ffffc9000c34faf0 RBP: ffffc9000c34faf0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000004 R11: 00000000000866da R12: ffffc9000c34f738 R13: ffffc9000c34f6e8 R14: ffffc9000c34fb10 R15: ffffc9000c34f71c FS: 0000000000000000(0000) GS:ffff8881246b9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0396215e9c CR3: 000000000e380000 CR4: 00000000003526f0 Call Trace: deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline] unwind_next_frame+0x15d5/0x20a0 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4879 skb_kfree_head net/core/skbuff.c:1047 [inline] skb_free_head+0x114/0x210 net/core/skbuff.c:1059 skb_release_data+0x795/0x9e0 net/core/skbuff.c:1086 skb_release_all net/core/skbuff.c:1151 [inline] __kfree_skb net/core/skbuff.c:1165 [inline] consume_skb net/core/skbuff.c:1397 [inline] consume_skb+0xbf/0x100 net/core/skbuff.c:1391 nsim_dev_trap_report drivers/net/netdevsim/dev.c:836 [inline] nsim_dev_trap_report_work+0x8bd/0xcf0 drivers/net/netdevsim/dev.c:866 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 vkms_vblank_simulate: vblank timer overrun