rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12802/1:b..l rcu: (detected by 0, t=10502 jiffies, g=53829, q=201 ncpus=2) task:syz.3.2060 state:R running task stack:26472 pid:12802 tgid:12802 ppid:5823 task_flags:0x40004c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1765 [inline] zap_pmd_range mm/memory.c:1827 [inline] zap_pud_range mm/memory.c:1856 [inline] zap_p4d_range mm/memory.c:1877 [inline] unmap_page_range+0x3842/0x41c0 mm/memory.c:1898 unmap_single_vma mm/memory.c:1941 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1985 exit_mmap+0x248/0xb50 mm/mmap.c:1284 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x648/0x22e0 kernel/exit.c:952 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 __do_sys_exit_group kernel/exit.c:1116 [inline] __se_sys_exit_group kernel/exit.c:1114 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f85d4b8e929 RSP: 002b:00007ffd4aeec838 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f85d4b8e929 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd4aeec89c R08: 00000000000001f4 R09: 000000000000004a R10: 00000000003ffbe8 R11: 0000000000000246 R12: 0000000000000190 R13: 000000000000004a R14: 00000000000d0088 R15: 00007ffd4aeec8f0 rcu: rcu_preempt kthread starved for 10523 jiffies! g53829 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12807 Comm: syz.0.2061 Not tainted 6.16.0-rc3-syzkaller-00057-g92ca6c498a5e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 14 e8 f8 0b 48 89 de 5b e9 c3 90 56 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 d0 99 92 65 8b 15 f8 83 RSP: 0018:ffffc90000a07e58 EFLAGS: 00000016 RAX: ffffffff81a23e23 RBX: 0000000000118c10 RCX: ffff888030510000 RDX: 0000000000000002 RSI: 0000000000118c10 RDI: 0000000000000001 RBP: ffffc90000a07fe0 R08: ffff888030510000 R09: 0000000000000003 R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000 R13: ffffffff8e056e60 R14: 0000000000000002 R15: ffffc90000a07ff0 FS: 0000555584d1e500(0000) GS:ffff888125d83000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f420224 CR3: 000000004a3c8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1894 [inline] prb_read kernel/printk/printk_ringbuffer.c:1942 [inline] _prb_read_valid+0xa7b/0xa90 kernel/printk/printk_ringbuffer.c:2113 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2185 printk_get_next_message+0x15c/0x7b0 kernel/printk/printk.c:3005 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x4ca/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4917 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4928 _dev_warn+0x10a/0x160 drivers/base/core.c:4984 usb_rx_callback_intf0+0x149/0x190 drivers/media/rc/imon.c:1768 __usb_hcd_giveback_urb+0x417/0x690 drivers/usb/core/hcd.c:1650 dummy_timer+0x862/0x4550 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5264 Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 e9 27 05 00 00 4c 8b 75 d0 4c 89 e7 e8 ff 48 d0 09 e8 0a fd 35 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc90004247758 EFLAGS: 00000282 RAX: eae382d78b401400 RBX: 0000000000000000 RCX: eae382d78b401400 RDX: 0000000000000000 RSI: ffffffff8d96ea60 RDI: ffffffff8be1b9c0 RBP: ffffc900042477b0 R08: ffffffff8f9fe1f7 R09: 1ffffffff1f3fc3e R10: dffffc0000000000 R11: fffffbfff1f3fc3f R12: ffff888030510000 R13: dffffc0000000000 R14: ffff888022305a00 R15: ffff8880b873a9d8 context_switch kernel/sched/core.c:5399 [inline] __schedule+0x16aa/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 futex_do_wait kernel/futex/waitwake.c:358 [inline] __futex_wait+0x1c3/0x3e0 kernel/futex/waitwake.c:687 futex_wait+0x104/0x360 kernel/futex/waitwake.c:715 do_futex+0x333/0x420 kernel/futex/syscalls.c:102 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:160 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f78bdb8e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd31066a58 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00000000000eaa7b RCX: 00007f78bdb8e929 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f78bddb608c RBP: 0000000000000032 R08: 7fffffffffffffff R09: 0000000e31066d4f R10: 00007ffd31066b50 R11: 0000000000000246 R12: 00007f78bddb608c R13: 00007ffd31066b50 R14: 00000000000eaaad R15: 00007ffd31066b70 imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored imon 4-1:155.0: imon usb_rx_callback_intf0: status(-71): ignored