rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15105/1:b..l rcu: (detected by 1, t=10502 jiffies, g=82089, q=1177 ncpus=2) task:syz.6.2347 state:R running task stack:26040 pid:15105 tgid:15101 ppid:13450 task_flags:0x40044c flags:0x10080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:kasan_check_range+0x9/0x2c0 mm/kasan/generic.c:199 Code: 88 97 8d e8 49 03 01 ff 90 0f 0b cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 41 57 41 56 <41> 55 41 54 53 b0 01 48 85 f6 0f 84 ba 01 00 00 4c 8d 04 37 49 39 RSP: 0018:ffffc9001840ef00 EFLAGS: 00000246 RAX: ffffffff8232a4c4 RBX: ffff88801cd8c2bc RCX: ffffffff8232a4dd RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88801cd8c2bc RBP: 0000000000000000 R08: ffff88801cd8c2bb R09: 1ffff110039b1857 R10: dffffc0000000000 R11: ffffed10039b1858 R12: 0000000000000000 R13: 0000000000054f3c R14: dffffc0000000000 R15: ffff88801cd8c270 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] __page_table_check_zero+0x1fd/0x3e0 mm/page_table_check.c:143 page_table_check_free include/linux/page_table_check.h:43 [inline] free_pages_prepare mm/page_alloc.c:1434 [inline] free_unref_folios+0xdc7/0x14f0 mm/page_alloc.c:3030 folios_put_refs+0x584/0x670 mm/swap.c:1002 free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:355 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:397 [inline] tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404 zap_pte_range mm/memory.c:1893 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x3962/0x4170 mm/memory.c:2017 unmap_single_vma mm/memory.c:2059 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2101 exit_mmap+0x239/0xb10 mm/mmap.c:1277 __mmput+0x118/0x430 kernel/fork.c:1173 exit_mm+0x169/0x230 kernel/exit.c:581 do_exit+0x627/0x22f0 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] __do_fast_syscall_32+0x398/0x570 arch/x86/entry/syscall_32.c:310 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf709d539 RSP: 002b:00000000f544b55c EFLAGS: 00000206 ORIG_RAX: 0000000000000151 RAX: fffffffffffffe00 RBX: 0000000000000005 RCX: 0000000080002ec0 RDX: 0000000000000ec0 RSI: 0000000000000002 RDI: 00000000800001c0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10532 jiffies! g82089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28008 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: usb 3-1: hanwang_irq - nonzero urb status received: -71 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9552 Comm: kworker/0:7 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:__sanitizer_cov_trace_switch+0x6c/0x130 kernel/kcov.c:350 Code: 83 f9 07 0f 85 d1 00 00 00 b9 07 00 00 00 48 85 c0 75 13 e9 c2 00 00 00 b9 01 00 00 00 48 85 c0 0f 84 b4 00 00 00 41 57 41 56 <41> 54 53 48 8b 54 24 20 65 4c 8b 04 25 08 40 80 92 45 31 c9 eb 08 RSP: 0000:ffffc90000006e38 EFLAGS: 00000002 RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000001 RDX: ffffc90002191000 RSI: ffffffff8f696a50 RDI: 0000000000000000 RBP: ffffffff8b6bb9c0 R08: ffffc90000006fb7 R09: 0000000000000000 R10: ffffc90000006fa0 R11: fffff52000000df7 R12: ffffc90000006fa0 R13: ffffc90000006ef8 R14: 0000000000000000 R15: ffffffff8b6bb9c0 FS: 0000000000000000(0000) GS:ffff888125e1c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f540c510 CR3: 00000000662dc000 CR4: 00000000003526f0 Call Trace: format_decode+0x2f/0xe10 lib/vsprintf.c:2670 vsnprintf+0x102/0xee0 lib/vsprintf.c:2889 sprintf+0xd9/0x120 lib/vsprintf.c:3110 print_caller kernel/printk/printk.c:1368 [inline] info_print_prefix+0x1f3/0x310 kernel/printk/printk.c:1385 record_print_text+0x154/0x420 kernel/printk/printk.c:1432 printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:3018 console_emit_next_record kernel/printk/printk.c:3083 [inline] console_flush_one_record kernel/printk/printk.c:3215 [inline] console_flush_all+0x4fb/0xb00 kernel/printk/printk.c:3289 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3359 vprintk_emit+0x47b/0x550 kernel/printk/printk.c:2426 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925 _dev_err+0x10a/0x160 drivers/base/core.c:4980 hanwang_irq+0x518/0x18d0 drivers/input/tablet/hanwang.c:268 __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1661 dummy_timer+0x85f/0x45b0 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1858 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x60/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d8/0x3b0 kernel/locking/lockdep.c:5893 Code: 63 e2 10 00 00 00 00 eb b5 e8 d4 ee bb 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 c4 1d e2 10 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 71 57 e7 RSP: 0000:ffffc9001c3c6740 EFLAGS: 00000282 RAX: 533f6c4a505e4c00 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000004 RSI: ffffffff8d97791e RDI: ffffffff8bc08760 RBP: ffff888079aae750 R08: ffffc9001c3c6980 R09: 0000000000000000 R10: ffffc9001c3c6898 R11: fffff52003878d15 R12: 0000000000000004 R13: 0000000000000004 R14: ffffffff8df41aa0 R15: ffff888079aadb80 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+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695 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:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270 __kernfs_new_node+0xdc/0x8a0 fs/kernfs/dir.c:637 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:718 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:82 [inline] internal_create_group+0x667/0x1170 fs/sysfs/group.c:189 internal_create_groups fs/sysfs/group.c:229 [inline] sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:255 device_add_groups drivers/base/core.c:2836 [inline] device_add_attrs+0x1c4/0x5a0 drivers/base/core.c:2911 device_add+0x496/0xb80 drivers/base/core.c:3643 usb_create_ep_devs+0x12c/0x230 drivers/usb/core/endpoint.c:170 create_intf_ep_devs drivers/usb/core/message.c:1252 [inline] usb_set_configuration+0x1bc7/0x2110 drivers/usb/core/message.c:2216 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c4/0x3c0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0xad0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1086 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574 device_add+0x7b6/0xb80 drivers/base/core.c:3689 usb_new_device+0xa39/0x1720 drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x29b1/0x4ef0 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - nonzero urb status received: -71 usb 3-1: hanwang_irq - usb_submit_urb failed with result -19