rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=004c/1/0x4000000000000000 softirq=77536/77545 fqs=0 rcu: (detected by 0, t=10506 jiffies, g=79485, q=78 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9220 Comm: kworker/1:5 Not tainted 6.14.0-rc7-syzkaller-00205-g586de92313fc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:299 Code: 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 RSP: 0018:ffffc90000a28df0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88802a783340 RCX: ffff8880b872c7d0 RDX: 1ffff110170e58fa RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880b872c780 R08: 0000000000000006 R09: 0000000000000001 R10: ffff88802a783340 R11: 0000000000000008 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880b872c680 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c39cc27 CR3: 000000007d4c8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __remove_hrtimer+0xa5/0x290 kernel/time/hrtimer.c:1133 __run_hrtimer kernel/time/hrtimer.c:1781 [inline] __hrtimer_run_queues+0x50b/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_flush_all+0x9a4/0xc60 kernel/printk/printk.c:3211 Code: 00 e8 90 01 28 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 5e 44 20 00 48 85 db 0f 85 55 01 00 00 e8 20 49 20 00 fb 4c 89 e0 <48> c1 e8 03 42 80 3c 38 00 0f 84 11 ff ff ff 4c 89 e7 e8 b5 61 83 RSP: 0018:ffffc90003a1f478 EFLAGS: 00000287 RAX: ffffffff8eead078 RBX: 0000000000000000 RCX: ffffc9001ad94000 RDX: 0000000000100000 RSI: ffffffff8199a750 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000008 R12: ffffffff8eead078 R13: ffffffff8eead020 R14: ffffc90003a1f508 R15: dffffc0000000000 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3309 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2432 dev_vprintk_emit drivers/base/core.c:4891 [inline] dev_printk_emit+0xfb/0x140 drivers/base/core.c:4902 __dev_printk+0xf5/0x270 drivers/base/core.c:4914 _dev_info+0xe5/0x120 drivers/base/core.c:4960 hub_port_init+0x11ac/0x3a40 drivers/usb/core/hub.c:4962 hub_port_connect drivers/usb/core/hub.c:5462 [inline] hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] port_event drivers/usb/core/hub.c:5833 [inline] hub_event+0x2b4f/0x4e10 drivers/usb/core/hub.c:5915 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10506 jiffies! g79485 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:27168 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 17071 Comm: syz.1.2957 Not tainted 6.14.0-rc7-syzkaller-00205-g586de92313fc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x4c6/0x12c0 kernel/smp.c:885 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 fc 4c 89 fd 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 ac 0e 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 e8 0b 00 00 8b 43 08 31 RSP: 0018:ffffc9000cc47820 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8744a80 RCX: ffffffff81ade1ea RDX: ffff888027194880 RSI: ffffffff81ade1c4 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffed10170e8951 R13: 0000000000000001 R14: ffff8880b863fe80 R15: ffff8880b8744a88 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f61cff8 CR3: 000000005ff4c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:966 [inline] flush_tlb_mm_range+0x271/0x4a0 arch/x86/mm/tlb.c:1054 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:481 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:471 [inline] tlb_flush_mmu mm/mmu_gather.c:395 [inline] tlb_finish_mmu+0x3c9/0x7b0 mm/mmu_gather.c:488 exit_mmap+0x40e/0xba0 mm/mmap.c:1297 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:570 [inline] do_exit+0x9ba/0x2db0 kernel/exit.c:925 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x24ed/0x26c0 kernel/signal.c:3036 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff98b38d169 Code: Unable to access opcode bytes at 0x7ff98b38d13f. RSP: 002b:00007ff98c21b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007ff98b5a5fa8 RCX: 00007ff98b38d169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff98b5a5fa8 RBP: 00007ff98b5a5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff98b5a5fac R13: 0000000000000000 R14: 00007ffd4dde7dc0 R15: 00007ffd4dde7ea8 watchdog: BUG: soft lockup - CPU#0 stuck for 246s! [syz.1.2957:17071] Modules linked in: irq event stamp: 556308 hardirqs last enabled at (556307): [] irqentry_exit+0x3b/0x90 kernel/entry/common.c:357 hardirqs last disabled at (556308): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1049 softirqs last enabled at (556300): [] softirq_handle_end kernel/softirq.c:407 [inline] softirqs last enabled at (556300): [] handle_softirqs+0x5bb/0x8f0 kernel/softirq.c:589 softirqs last disabled at (556245): [] __do_softirq kernel/softirq.c:595 [inline] softirqs last disabled at (556245): [] invoke_softirq kernel/softirq.c:435 [inline] softirqs last disabled at (556245): [] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:662 CPU: 0 UID: 0 PID: 17071 Comm: syz.1.2957 Not tainted 6.14.0-rc7-syzkaller-00205-g586de92313fc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x4c6/0x12c0 kernel/smp.c:885 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 fc 4c 89 fd 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 ac 0e 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 e8 0b 00 00 8b 43 08 31 RSP: 0018:ffffc9000cc47820 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8744a80 RCX: ffffffff81ade1ea RDX: ffff888027194880 RSI: ffffffff81ade1c4 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffed10170e8951 R13: 0000000000000001 R14: ffff8880b863fe80 R15: ffff8880b8744a88 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f61cff8 CR3: 000000005ff4c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:966 [inline] flush_tlb_mm_range+0x271/0x4a0 arch/x86/mm/tlb.c:1054 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:481 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:471 [inline] tlb_flush_mmu mm/mmu_gather.c:395 [inline] tlb_finish_mmu+0x3c9/0x7b0 mm/mmu_gather.c:488 exit_mmap+0x40e/0xba0 mm/mmap.c:1297 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:570 [inline] do_exit+0x9ba/0x2db0 kernel/exit.c:925 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x24ed/0x26c0 kernel/signal.c:3036 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff98b38d169 Code: Unable to access opcode bytes at 0x7ff98b38d13f. RSP: 002b:00007ff98c21b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007ff98b5a5fa8 RCX: 00007ff98b38d169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff98b5a5fa8 RBP: 00007ff98b5a5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff98b5a5fac R13: 0000000000000000 R14: 00007ffd4dde7dc0 R15: 00007ffd4dde7ea8 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9220 Comm: kworker/1:5 Not tainted 6.14.0-rc7-syzkaller-00205-g586de92313fc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:__kasan_check_read+0x8/0x20 mm/kasan/shadow.c:31 Code: 60 48 c7 c7 08 15 80 8d 5b 5d 41 5c e9 a1 33 7c ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 <89> f6 31 d2 e9 7f f0 ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f RSP: 0018:ffffc90000a28a88 EFLAGS: 00000003 RAX: 0000000000000001 RBX: 0000000000000070 RCX: ffffffff8195c64e RDX: 1ffff11005568185 RSI: 0000000000000008 RDI: ffffffff96ec6cc8 RBP: ffffc90000a28bd8 R08: 0000000000000007 R09: 0000000000000001 R10: ffffffff96ec6ccf R11: 0000000000000007 R12: ffff88802ab40000 R13: 0000000000000001 R14: 0000000000000000 R15: 1ffff9200014515a FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c39cc27 CR3: 000000007d4c8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class+0x4e/0x130 kernel/locking/lockdep.c:230 mark_lock+0xb5/0xc60 kernel/locking/lockdep.c:4729 mark_usage kernel/locking/lockdep.c:4637 [inline] __lock_acquire+0x1390/0x3c40 kernel/locking/lockdep.c:5182 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1805 [inline] __hrtimer_run_queues+0x2be/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_flush_all+0x9a4/0xc60 kernel/printk/printk.c:3211 Code: 00 e8 90 01 28 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 5e 44 20 00 48 85 db 0f 85 55 01 00 00 e8 20 49 20 00 fb 4c 89 e0 <48> c1 e8 03 42 80 3c 38 00 0f 84 11 ff ff ff 4c 89 e7 e8 b5 61 83 RSP: 0018:ffffc90003a1f478 EFLAGS: 00000287 RAX: ffffffff8eead078 RBX: 0000000000000000 RCX: ffffc9001ad94000 RDX: 0000000000100000 RSI: ffffffff8199a750 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000008 R12: ffffffff8eead078 R13: ffffffff8eead020 R14: ffffc90003a1f508 R15: dffffc0000000000 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3309 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2432 dev_vprintk_emit drivers/base/core.c:4891 [inline] dev_printk_emit+0xfb/0x140 drivers/base/core.c:4902 __dev_printk+0xf5/0x270 drivers/base/core.c:4914 _dev_info+0xe5/0x120 drivers/base/core.c:4960 hub_port_init+0x11ac/0x3a40 drivers/usb/core/hub.c:4962 hub_port_connect drivers/usb/core/hub.c:5462 [inline] hub_port_connect_change drivers/usb/core/hub.c:5673 [inline] port_event drivers/usb/core/hub.c:5833 [inline] hub_event+0x2b4f/0x4e10 drivers/usb/core/hub.c:5915 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244