INFO: task syz.1.849:9236 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.849 state:D stack:27176 pid:9236 tgid:9232 ppid:5806 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7005 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 sync_bdevs+0x153/0x480 block/bdev.c:1304 ksys_sync+0xb0/0xf0 fs/sync.c:105 __do_sys_sync+0xe/0x20 fs/sync.c:111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f05ced9c799 RSP: 002b:00007f05cfc83028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f05cf016180 RCX: 00007f05ced9c799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f05cf016180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f05cf016218 R14: 00007f05cf016180 R15: 00007ffe97cad738 Showing all locks held in the system: 3 locks held by kworker/1:0/24: #0: ffff88813fe67148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250 #1: ffffc900001e7d08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251 #2: ffffffff8e7f31b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by khungtaskd/30: #0: ffffffff8e7e75a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e75a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e75a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 5 locks held by kworker/1:1/50: #0: ffff8880236ca148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250 #1: ffffc90000ba7d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251 #2: ffff88802a50c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88802a50c198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88802a518518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #3: ffff88802a518518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #3: ffff88802a518518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #3: ffff88802a518518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #3: ffff88802a518518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2bd2/0x4af0 drivers/usb/core/hub.c:5953 #4: ffff888029f2d568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline] #4: ffff888029f2d568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #4: ffff888029f2d568 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #4: ffff888029f2d568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2bfb/0x4af0 drivers/usb/core/hub.c:5953 2 locks held by getty/5566: #0: ffff888038a580a0 (&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+0x419/0x1500 drivers/tty/n_tty.c:2211 5 locks held by kworker/0:3/5812: #0: ffff8880236ca148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250 #1: ffffc900026f7d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251 #2: ffff88802a657198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88802a657198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88805f32d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff88805f32d198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008 #4: ffff88805d320160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88805d320160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008 1 lock held by udevd/6009: #0: ffff88802741a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961 1 lock held by syz.1.849/9236: #0: ffff88802741a358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304 2 locks held by syz.0.878/9342: #0: ffff88807af1e0e0 (&type->s_umount_key#28/1){+.+.}-{4:4}, at: alloc_super+0x244/0xd20 fs/super.c:345 #1: ffff88802741a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xa2/0xe40 block/bdev.c:961 4 locks held by syz.6.1271/10790: #0: ffff888031e28ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 #1: ffff888031e280c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5346 #2: ffffffff908a9688 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff908a9688 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2644 #3: ffff88807961e2f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x770 net/bluetooth/l2cap_core.c:1755 3 locks held by syz.7.1273/10794: #0: ffff888034e30ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 #1: ffff888034e300c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5346 #2: ffffffff908a9688 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff908a9688 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2644 2 locks held by syz.5.1277/10803: #0: ffffffff906112e8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff906112e8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436 #1: ffffffff8e7f31b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by syz.2.1281/10811: #0: ffffffff906112e8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff906112e8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 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: 35 Comm: kworker/u8:2 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1108 [inline] RIP: 0010:debug_check_no_obj_freed+0x210/0x630 lib/debugobjects.c:1146 Code: 00 00 48 89 c2 31 f6 49 89 df 4c 89 74 24 28 48 c1 ea 03 89 f3 42 80 3c 22 00 0f 85 dd 00 00 00 48 8d 78 18 83 c3 01 4c 8b 30 <48> 89 fa 48 c1 ea 03 42 80 3c 22 00 0f 85 27 03 00 00 48 8b 50 18 RSP: 0018:ffffc90000ab7930 EFLAGS: 00000002 RAX: ffff8881404a27a8 RBX: 0000000000000002 RCX: ffffffff81e53498 RDX: 1ffff110280944f5 RSI: 0000000000000000 RDI: ffff8881404a27c0 RBP: ffffc90000ab7a60 R08: 0000000000000001 R09: fffff52000156f14 R10: 0000000000000003 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88807b892d80 R14: ffff88805ddbbaf0 R15: ffff88807b893040 FS: 0000000000000000(0000) GS:ffff888124345000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005557179bb000 CR3: 000000000e598000 CR4: 00000000003526f0 Call Trace: slab_free_hook mm/slub.c:2616 [inline] slab_free mm/slub.c:6165 [inline] kmem_cache_free+0x3c8/0x6a0 mm/slub.c:6295 skb_kfree_head net/core/skbuff.c:1087 [inline] skb_kfree_head net/core/skbuff.c:1084 [inline] skb_free_head+0x1c6/0x220 net/core/skbuff.c:1101 skb_release_data+0x79b/0x9d0 net/core/skbuff.c:1128 skb_release_all net/core/skbuff.c:1203 [inline] __kfree_skb net/core/skbuff.c:1217 [inline] consume_skb net/core/skbuff.c:1450 [inline] consume_skb+0xc4/0x110 net/core/skbuff.c:1444 ieee80211_iface_work+0x468/0x13d0 net/mac80211/iface.c:1804 cfg80211_wiphy_work+0x446/0x5c0 net/wireless/core.c:440 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245