INFO: task syz.4.372:7249 blocked for more than 143 seconds. Not tainted 6.15.0-syzkaller-10815-gbb1556ec9464 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.372 state:D stack:28632 pid:7249 tgid:7248 ppid:5814 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6781 __schedule_loop kernel/sched/core.c:6859 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6874 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6931 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 nbd_start_device_ioctl drivers/block/nbd.c:1542 [inline] __nbd_ioctl drivers/block/nbd.c:1602 [inline] nbd_ioctl+0x30a/0xda0 drivers/block/nbd.c:1642 blkdev_ioctl+0x274/0x6d0 block/ioctl.c:704 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 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: 0033:0x7fa9d778e969 RSP: 002b:00007fa9d8530038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa9d79b5fa0 RCX: 00007fa9d778e969 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007fa9d7810ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa9d79b5fa0 R15: 00007fff3cfb7fd8 INFO: task syz.4.372:7253 blocked for more than 143 seconds. Not tainted 6.15.0-syzkaller-10815-gbb1556ec9464 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.372 state:D stack:28248 pid:7253 tgid:7248 ppid:5814 task_flags:0x480140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6781 __schedule_loop kernel/sched/core.c:6859 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6874 blk_mq_freeze_queue_wait+0x143/0x1b0 block/blk-mq.c:190 blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] queue_limits_commit_update_frozen+0x93/0x110 block/blk-settings.c:482 nbd_set_size+0x4e7/0x730 drivers/block/nbd.c:374 __nbd_ioctl drivers/block/nbd.c:1593 [inline] nbd_ioctl+0xd34/0xda0 drivers/block/nbd.c:1642 blkdev_ioctl+0x274/0x6d0 block/ioctl.c:704 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 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: 0033:0x7fa9d778e969 RSP: 002b:00007fa9d850f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa9d79b6080 RCX: 00007fa9d778e969 RDX: 0000000000000582 RSI: 000000000000ab07 RDI: 0000000000000003 RBP: 00007fa9d7810ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fa9d79b6080 R15: 00007fff3cfb7fd8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 2 locks held by dhcpcd/5478: #0: ffff888077f0b6d0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0x9c7/0xce0 net/netlink/af_netlink.c:2255 #1: ffffffff90346fa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff90346fa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x18f/0x1f0 net/core/rtnetlink.c:6812 2 locks held by getty/5576: #0: ffff8880320330a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fee2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by udevd/5799: #0: ffff8880268df358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 2 locks held by kworker/0:4/5858: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000483fd10 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 1 lock held by syz.4.372/7249: #0: ffff888142f70a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_start_device_ioctl drivers/block/nbd.c:1542 [inline] #0: ffff888142f70a30 (&nbd->config_lock){+.+.}-{4:4}, at: __nbd_ioctl drivers/block/nbd.c:1602 [inline] #0: ffff888142f70a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x30a/0xda0 drivers/block/nbd.c:1642 4 locks held by syz.4.372/7253: #0: ffff888142f70a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x150/0xda0 drivers/block/nbd.c:1635 #1: ffff888142f690c8 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1002 [inline] #1: ffff888142f690c8 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x2c3/0x730 drivers/block/nbd.c:354 #2: ffff888142f68a70 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 block/blk-mq.c:205 #3: ffff888142f68aa8 (&q->q_usage_counter(queue)#5){+.+.}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 block/blk-mq.c:205 1 lock held by syz.0.408/7418: #0: ffffffff8e5d0338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 3 locks held by kworker/u8:23/8073: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000487fd10 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90346fa8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 2 locks held by kworker/u8:30/8090: #0: ffff8880b853bc58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:606 #1: ffff8880b8524048 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987 3 locks held by kworker/u8:44/8110: #0: ffff88801c6f3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003a57d10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90330f50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662 2 locks held by kworker/u8:48/8114: #0: ffff8880b843bc58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:606 #1: ffff8880b8424048 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987 1 lock held by syz.3.831/9237: #0: ffff8880268df358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0xfd/0x360 block/bdev.c:1288 1 lock held by syz.3.831/9240: #0: ffff8880268df358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0xfd/0x360 block/bdev.c:1288 1 lock held by syz.3.831/9242: #0: ffff8880268df358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0xfd/0x360 block/bdev.c:1288 7 locks held by syz-executor/11239: #0: ffff88803722e428 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #1: ffff888055fbd488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325 #2: ffff8880283335a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326 #3: ffffffff8f8e6588 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:216 #4: ffff888052cad0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff888052cad0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff888052cad0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1292 #5: ffff888052cab250 (&devlink->lock_key#20){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1d0 drivers/net/netdevsim/dev.c:1675 #6: ffffffff90346fa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff90346fa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2143 2 locks held by syz-executor/11326: #0: ffffffff8f70f1e0 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #0: ffffffff8f70f1e0 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #0: ffffffff8f70f1e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x113/0x2c0 net/core/rtnetlink.c:574 #1: ffffffff90346fa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff90346fa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff90346fa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4054 4 locks held by syz.8.1326/11450: #0: ffff888052294d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:481 #1: ffff888052294078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5213 #2: ffffffff905b8608 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2062 [inline] #2: ffffffff905b8608 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2543 #3: ffff888071919338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1762 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-10815-gbb1556ec9464 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c5/0x780 kernel/kthread.c:464 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 64 Comm: kworker/u8:4 Not tainted 6.15.0-syzkaller-10815-gbb1556ec9464 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound cfg80211_wiphy_work 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:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:lock_release+0x8d/0x2f0 kernel/locking/lockdep.c:5888 Code: 85 16 01 00 00 65 4c 8b 35 58 4d 33 12 41 8b b6 ec 0a 00 00 85 f6 0f 85 ff 00 00 00 48 81 3b 00 95 d2 93 0f 84 f2 00 00 00 9c <41> 5d fa 48 c7 c7 9a ae ef 8d e8 64 12 e5 09 65 ff 05 95 8e 33 12 RSP: 0018:ffffc9000213f4c8 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffffffff8e5c4d80 RCX: ffffffff91416301 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff914163ea R09: 0000000000000000 R10: 0000000000000000 R11: 000000000000a769 R12: ffffffff816abbe4 R13: ffffc9000213f588 R14: ffff88801e314880 R15: ffffc9000213f5bc FS: 0000000000000000(0000) GS:ffff888124865000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563d9decf000 CR3: 000000000e382000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479 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:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4841 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1574 [inline] ieee80211_ibss_rx_queued_mgmt+0x1a92/0x2fd0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1668 [inline] ieee80211_iface_work+0xbf4/0x1020 net/mac80211/iface.c:1722 cfg80211_wiphy_work+0x3dc/0x550 net/wireless/core.c:435 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245