INFO: task syz.6.1492:10857 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1492 state:D stack:26696 pid:10857 tgid:10856 ppid:9526 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5254 [inline] __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862 __schedule_loop kernel/sched/core.c:6944 [inline] schedule+0x165/0x360 kernel/sched/core.c:6959 super_lock+0x1c8/0x3b0 fs/super.c:115 __iterate_supers+0x126/0x290 fs/super.c:923 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a8938efc9 RSP: 002b:00007f4a8a164038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f4a895e5fa0 RCX: 00007f4a8938efc9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f4a895e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4a895e6038 R14: 00007f4a895e5fa0 R15: 00007ffc1d6fb9c8 Showing all locks held in the system: 6 locks held by kworker/0:1/10: 2 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/31: #0: ffffffff8e33d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5588: #0: ffff88814de140a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by udevd/5828: #0: ffff888058bf69e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 #1: ffff88806bff3088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff8880b8624048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #3: ffffffff8e33d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #3: ffffffff8e33d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #3: ffffffff8e33d8a0 (rcu_read_lock){....}-{1:3}, at: is_bpf_text_address+0x26/0x2b0 kernel/bpf/core.c:744 4 locks held by kworker/1:7/5917: #0: ffff8880206c8d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242 #1: ffffc900045bfba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243 #2: ffff8880280df198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff8880280df198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff8880281b2518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #3: ffff8880281b2518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x639/0x4ef0 drivers/usb/core/hub.c:5952 1 lock held by syz.2.1077/9354: #0: ffff88805dcd60e0 (&type->s_umount_key#86/1){+.+.}-{4:4}, at: alloc_super+0x1bb/0x960 fs/super.c:344 6 locks held by kworker/1:0/10277: #0: ffff88801b055948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242 #1: ffffc900040afba0 ((work_completion)(&intf->reset_ws)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243 #2: ffff88805ec03198 (&dev->mutex){....}-{4:4}, at: device_trylock include/linux/device.h:924 [inline] #2: ffff88805ec03198 (&dev->mutex){....}-{4:4}, at: usb_lock_device_for_reset+0x123/0x340 drivers/usb/core/usb.c:907 #3: ffff8880281b2518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #3: ffff8880281b2518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_reset_device+0x549/0xb50 drivers/usb/core/hub.c:6409 #4: ffff888028043368 (hcd->address0_mutex){+.+.}-{4:4}, at: usb_reset_and_verify_device+0x372/0x1ad0 drivers/usb/core/hub.c:6204 #5: ffffffff8efb4750 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x14e/0x1850 drivers/usb/core/hub.c:3067 3 locks held by syz.1.2076/12898: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:337 [inline] watchdog+0xfa9/0xff0 kernel/hung_task.c:500 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 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: 1160 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__lock_release kernel/locking/lockdep.c:5546 [inline] RIP: 0010:lock_release+0x14d/0x3e0 kernel/locking/lockdep.c:5889 Code: a9 7b bf 09 44 89 64 24 14 45 89 e5 85 c0 0f 84 dd 00 00 00 48 85 ed 0f 84 19 01 00 00 83 7d 24 00 0f 85 ea 01 00 00 8b 45 20 <3d> 00 00 20 00 48 8b 5c 24 08 8b 54 24 14 72 25 89 c1 81 e1 00 00 RSP: 0018:ffffc90003f1f410 EFLAGS: 00000046 RAX: 0000000000020007 RBX: 0000000000000014 RCX: 7aee38463789b000 RDX: ffffc90003f1f501 RSI: ffffffff8e33d8a0 RDI: ffff888027088bd0 RBP: ffff888027088bd0 R08: ffffc90003f1fd70 R09: 0000000000000000 R10: ffffc90003f1f598 R11: fffff520007e3eb5 R12: 0000000000000004 R13: 0000000000000004 R14: ffffffff8e33d8a0 R15: ffff888027088000 FS: 0000000000000000(0000) GS:ffff888125b9f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d6ddb3ad8 CR3: 000000000e138000 CR4: 00000000003526f0 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4984 [inline] slab_alloc_node mm/slub.c:5294 [inline] kmem_cache_alloc_node_noprof+0x43c/0x710 mm/slub.c:5346 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:663 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:763 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:866 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267 process_scheduled_works kernel/workqueue.c:3350 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245