rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=a88c/1/0x4000000000000000 softirq=87839/87840 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15396/1:b..l
rcu: (detected by 0, t=10506 jiffies, g=84453, q=864 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 15408 Comm: syz.0.1909 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rb_erase_cached include/linux/rbtree.h:151 [inline]
RIP: 0010:timerqueue_del+0x66/0x100 lib/timerqueue.c:57
Code: 3e 4c 89 ff 4c 89 f6 e8 b8 31 68 f6 4d 39 f7 0f 84 9d 00 00 00 e8 4a 2f 68 f6 4c 8d 63 08 4d 89 e7 49 c1 ef 03 43 80 3c 2f 00 <74> 08 4c 89 e7 e8 b0 d7 ce f6 4d 39 34 24 74 07 e8 25 2f 68 f6 eb
RSP: 0018:ffffc90000a08d08 EFLAGS: 00000046
RAX: ffffffff8b598916 RBX: ffff8880b8728390 RCX: ffff88807df31e80
RDX: 0000000000010000 RSI: ffff88801ff35300 RDI: ffff888030777c00
RBP: 1ffff11003fe6a60 R08: ffffffff8fa22f77 R09: 1ffffffff1f445ee
R10: dffffc0000000000 R11: fffffbfff1f445ef R12: ffff8880b8728398
R13: dffffc0000000000 R14: ffff88801ff35300 R15: 1ffff110170e5073
FS: 0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3be7fc CR3: 000000003064a000 CR4: 00000000003526f0
Call Trace:
__remove_hrtimer kernel/time/hrtimer.c:1114 [inline]
__run_hrtimer kernel/time/hrtimer.c:1757 [inline]
__hrtimer_run_queues+0x364/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_is_held_type+0x137/0x190 kernel/locking/lockdep.c:5945
Code: 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 05 49 fa 41 07 <48> 3b 44 24 08 75 43 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9000cbe7498 EFLAGS: 00000206
RAX: f1bb428af2cb2000 RBX: 0000000000000000 RCX: f1bb428af2cb2000
RDX: 0000000000000000 RSI: ffffffff8db7ed49 RDI: ffffffff8be07960
RBP: 00000000ffffffff R08: ffff8880324b4de3 R09: 1ffff110064969bc
R10: dffffc0000000000 R11: ffffed10064969bd R12: 0000000000000246
R13: ffff88807df31e80 R14: ffffffff8e13f3a0 R15: 0000000000000001
lock_is_held include/linux/lockdep.h:249 [inline]
__might_resched+0xf5/0x610 kernel/sched/core.c:8794
zap_pud_range mm/memory.c:1977 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x6d7/0x44e0 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:1177
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x850/0x25b0 kernel/exit.c:959
__do_sys_exit kernel/exit.c:1079 [inline]
__se_sys_exit kernel/exit.c:1077 [inline]
__x64_sys_exit+0x40/0x40 kernel/exit.c:1077
x64_sys_call+0x21f3/0x2210 arch/x86/include/generated/asm/syscalls_64.h:61
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f339698f749
Code: Unable to access opcode bytes at 0x7f339698f71f.
RSP: 002b:00007f3394bf5fe8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007f3396be5fa0 RCX: 00007f339698f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f3396a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3396be6038 R14: 00007f3396be5fa0 R15: 00007ffe2d6e3388
task:syz.9.1904 state:R running task stack:25056 pid:15396 tgid:15394 ppid:9383 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7050
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7074
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
timerfd_clock_was_set+0x1ce/0x2c0 fs/timerfd.c:111
clock_was_set+0x73b/0x7c0 kernel/time/hrtimer.c:975
do_adjtimex+0x228/0x310 kernel/time/timekeeping.c:2767
do_clock_adjtime kernel/time/posix-timers.c:1161 [inline]
__do_sys_clock_adjtime kernel/time/posix-timers.c:1173 [inline]
__se_sys_clock_adjtime kernel/time/posix-timers.c:1164 [inline]
__x64_sys_clock_adjtime+0x211/0x2c0 kernel/time/posix-timers.c:1164
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4237f8f749
RSP: 002b:00007f4238e5e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131
RAX: ffffffffffffffda RBX: 00007f42381e5fa0 RCX: 00007f4237f8f749
RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000000
RBP: 00007f4238013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42381e6038 R14: 00007f42381e5fa0 R15: 00007ffcf9b13ee8
rcu: rcu_preempt kthread starved for 10506 jiffies! g84453 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:26840 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
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+0x599/0xb30 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:
CPU: 0 UID: 0 PID: 8754 Comm: kworker/u8:21 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: iou_exit io_ring_exit_work
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xccf/0x12b0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 aa a6 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 55 a2 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 39 a2
RSP: 0018:ffffc90002f97560 EFLAGS: 00000293
RAX: ffffffff81b61627 RBX: 1ffff110170e818d RCX: ffff88802a6cdb80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002f976e0 R08: ffffffff8fa22f77 R09: 1ffffffff1f445ee
R10: dffffc0000000000 R11: fffffbfff1f445ef R12: ffff8880b8740c68
R13: dffffc0000000000 R14: ffff8880b863bd40 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2c3954 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
__static_key_slow_dec_cpuslocked+0xbe/0x140 kernel/jump_label.c:315
__static_key_slow_dec kernel/jump_label.c:321 [inline]
static_key_slow_dec+0x45/0x90 kernel/jump_label.c:336
io_ring_ctx_free+0x363/0x530 io_uring/io_uring.c:2869
io_ring_exit_work+0x863/0x8d0 io_uring/io_uring.c:3076
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246