rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=fb7c/1/0x4000000000000000 softirq=88023/88023 fqs=0
rcu: (detected by 1, t=10502 jiffies, g=93477, q=531 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17021 Comm: syz.2.3203 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_release kernel/locking/lockdep.c:5885 [inline]
RIP: 0010:lock_release+0x8b/0x310 kernel/locking/lockdep.c:5875
Code: 39 01 00 00 65 4c 8b 25 fb b9 7d 12 41 8b bc 24 9c 0b 00 00 85 ff 0f 85 21 01 00 00 48 81 3b 80 e9 69 94 0f 84 14 01 00 00 9c <41> 5e fa 48 c7 c7 71 87 29 8e e8 26 15 d3 09 65 ff 05 7f 00 7e 12
RSP: 0018:ffffc90000007d48 EFLAGS: 00000006
RAX: 0000000000000000 RBX: ffffffff9b9cf580 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8c400b00 RDI: 0000000000000000
RBP: ffffffff8526b9e4 R08: 0000000000000001 R09: fffff52000000fa4
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888021744a80
R13: dffffc0000000000 R14: ffff888053bdd300 R15: 1ffff92000000fb8
FS: 00007faddc9c16c0(0000) GS:ffff888123dee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000006680 CR3: 00000000381bd000 CR4: 00000000003526f0
DR0: 0000000000000084 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline]
_raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:198
debug_object_deactivate+0x2e4/0x3b0 lib/debugobjects.c:951
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:2000 [inline]
__hrtimer_run_queues+0x2e9/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 96 0e 2a f6 48 89 df e8 1e 5e 2a f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 25 6f 19 f6 65 8b 05 ee c8 a7 08 85 c0 74 16 5b
RSP: 0018:ffffc90005357d78 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff9b72d3d8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e1a235d RDI: ffffffff8c400b80
RBP: 0000000000000287 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffffffffffff R12: 1ffff92000a6afb6
R13: 000000000cedd660 R14: 000000000cedd660 R15: 0000000000000000
class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline]
do_settimeofday64+0x326/0x4d0 kernel/time/timekeeping.c:1665
do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195
__do_sys_clock_settime kernel/time/posix-timers.c:1139 [inline]
__se_sys_clock_settime kernel/time/posix-timers.c:1123 [inline]
__x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1123
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faddbb9de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007faddc9c1028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007faddbe25fa0 RCX: 00007faddbb9de59
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007faddbc33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faddbe26038 R14: 00007faddbe25fa0 R15: 00007ffca69b53b8
rcu: rcu_preempt kthread starved for 10502 jiffies! g93477 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:27528 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 17041 Comm: syz.1.3208 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 96 0e 2a f6 48 89 df e8 1e 5e 2a f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 25 6f 19 f6 65 8b 05 ee c8 a7 08 85 c0 74 16 5b
RSP: 0018:ffffc90000a08c48 EFLAGS: 00000246
RAX: 0000000000000016 RBX: ffff88802b3cc000 RCX: 0000000000000004
RDX: 0000000000000000 RSI: ffffffff8e1a235d RDI: ffffffff8c400b80
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88802b45b4a3 R15: ffff88802b45b410
FS: 0000000000000000(0000) GS:ffff888123eee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001bc030 CR3: 000000002ad2b000 CR4: 00000000003526f0
DR0: 0000000000000084 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
dummy_timer+0x1db5/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:2022
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2113
handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x16c0 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 b9 95 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 2c 0f 00 00 8b 45 08 31
RSP: 0018:ffffc9000463f8a8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fd3a8d
RDX: ffff888034ee8000 RSI: ffffffff81fd3a67 RDI: ffff888034ee8000
RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:499 [inline]
tlb_flush_mmu mm/mmu_gather.c:423 [inline]
tlb_finish_mmu+0x3fe/0x810 mm/mmu_gather.c:549
exit_mmap+0x454/0xa00 mm/mmap.c:1313
__mmput+0x12a/0x410 kernel/fork.c:1182
mmput+0x67/0x80 kernel/fork.c:1205
exit_mm kernel/exit.c:610 [inline]
do_exit+0x8b1/0x2ae0 kernel/exit.c:992
do_group_exit+0xd5/0x2a0 kernel/exit.c:1147
__do_sys_exit_group kernel/exit.c:1158 [inline]
__se_sys_exit_group kernel/exit.c:1156 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1156
x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f93ff59de59
Code: Unable to access opcode bytes at 0x7f93ff59de2f.
RSP: 002b:00007ffcfd61f3d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f93ff59de59
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffcfd61f43c R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000001f
R13: 00000000000927c0 R14: 00000000000c0ddd R15: 00007ffcfd61f490