rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-....: (2 ticks this GP) idle=0a4c/1/0x4000000000000000 softirq=30033/30033 fqs=3
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9093/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=31677, q=1541 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5640 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__lock_acquire+0x80a/0x2cf0 kernel/locking/lockdep.c:-1
Code: 6d 03 eb c3 89 e8 25 ff 1f 00 00 c1 ed 03 81 e5 00 60 00 00 09 c5 48 89 d8 48 c1 e8 20 29 c5 89 c1 c1 c1 04 31 e9 01 d8 29 cb <89> ca c1 c2 06 31 da 01 c1 29 d0 89 d6 c1 c6 08 31 c6 01 ca 29 f1
RSP: 0018:ffffc90000a08b20 EFLAGS: 00000887
RAX: 000000002f227b48 RBX: 00000000f02421e1 RCX: 0000000082ee3bcd
RDX: 0000000000000008 RSI: ffff88802b41e8c8 RDI: ffff88802b41dd00
RBP: 0000000043efe266 R08: ffffffff84de04e7 R09: 0000000000080000
R10: 0000000000000000 R11: ffffffff9aa3edc0 R12: ffff88802b41e8c8
R13: ffff88802b41e8c8 R14: ffff88802b41dd00 R15: 0000000000000001
FS: 0000555569c8f500(0000) GS:ffff888125058000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc43976612d CR3: 000000005c256000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
debug_object_activate+0xb7/0x420 lib/debugobjects.c:873
debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline]
debug_activate kernel/time/hrtimer.c:528 [inline]
enqueue_hrtimer+0xa9/0x2c0 kernel/time/hrtimer.c:1109
__run_hrtimer kernel/time/hrtimer.c:2048 [inline]
__hrtimer_run_queues+0x4ce/0xa10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:finish_task_switch+0x417/0xc60 kernel/sched/core.c:5361
Code: 04 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 63 ca 3c 0a e8 fe ab 39 00 fb 4c 8b 65 c8 <49> 8d bc 24 f8 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900046b7980 EFLAGS: 00000206
RAX: 00000000000c508b RBX: ffff8880b873bf20 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8e22a5a0 RDI: ffffffff8c4bd380
RBP: ffffc900046b79d0 R08: ffffffff905775f7 R09: 1ffffffff20aeebe
R10: dffffc0000000000 R11: fffffbfff20aeebf R12: ffff88802b41dd00
R13: ffff88802b41dd00 R14: dffffc0000000000 R15: 1ffff110170e77e4
context_switch kernel/sched/core.c:5513 [inline]
__schedule+0x17e1/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
do_nanosleep+0x21e/0x6a0 kernel/time/hrtimer.c:2399
hrtimer_nanosleep+0x18f/0x3a0 kernel/time/hrtimer.c:2445
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1406 [inline]
__se_sys_clock_nanosleep+0x35b/0x3b0 kernel/time/posix-timers.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6aaff5e68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fff499c4a78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000555569c8f500 RCX: 00007f6aaff5e68e
RDX: 00007fff499c4ad0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff499c4b3c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000000b4
R13: 0000000000000062 R14: 0000000000029a8c R15: 00007fff499c4b90
task:syz.0.935 state:R running task stack:26312 pid:9093 tgid:9093 ppid:5624 task_flags:0x400040 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7413
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
wp_page_copy mm/memory.c:3976 [inline]
do_wp_page+0x3ec0/0x4c70 mm/memory.c:4336
handle_pte_fault mm/memory.c:6395 [inline]
__handle_mm_fault mm/memory.c:6517 [inline]
handle_mm_fault+0x1490/0x3080 mm/memory.c:6686
do_user_addr_fault+0xa4d/0x1340 arch/x86/mm/fault.c:1343
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7ff9e22671b5
RSP: 002b:00007ffcfe81ea00 EFLAGS: 00010206
RAX: 0000000000000003 RBX: 0000000000029ad4 RCX: 00007ff9e26220c0
RDX: 00007ff9e26220c0 RSI: 0000000000000080 RDI: 00007ff9e2625fa0
RBP: 0000000000000032 R08: 00007ff9e2625fa0 R09: 0000000000000000
R10: 00007ffcfe81eb50 R11: 0000000000000246 R12: 00007ff9e2625fa0
R13: 00007ff9e2625fac R14: 0000000000029b06 R15: 00007ff9e2625fa0
rcu: rcu_preempt kthread starved for 4210 jiffies! g31677 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:27736 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 0 UID: 0 PID: 5619 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x10b5/0x14b0 kernel/smp.c:892
Code: 1e 89 de 83 e6 01 31 ff e8 d8 1e 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 84 1a 0c 00 eb 37 f3 90 41 0f b6 04 1c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 69 1a 0c 00 eb e5 44 89
RSP: 0018:ffffc900039775a0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888036050000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900039776c8 R08: ffff888035b318c7 R09: 1ffff11006b66318
R10: dffffc0000000000 R11: ffffed1006b66319 R12: 1ffff110170e81d1
R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124f58000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f34ae35da08 CR3: 00000000775aa000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 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+0x5c4/0x1090 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+0x1af/0xa30 mm/mmu_gather.c:423
tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:549
exit_mmap+0x4b2/0x9f0 mm/mmap.c:1313
__mmput+0x118/0x420 kernel/fork.c:1187
exit_mm+0x221/0x2d0 kernel/exit.c:610
do_exit+0x6cd/0x2360 kernel/exit.c:992
do_group_exit+0x22d/0x2f0 kernel/exit.c:1147
get_signal+0x121b/0x12c0 kernel/signal.c:3038
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9e2358fd7
Code: Unable to access opcode bytes at 0x7ff9e2358fad.
RSP: 002b:00007ffcfe81edd0 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 000055558121b500 RCX: 00007ff9e2358fd7
RDX: 0000000040000000 RSI: 00007ffcfe81ee2c RDI: ffffffffffffffff
RBP: 00007ffcfe81ee2c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffcfe81f088 R15: 0000000000000000