rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=6ecc/1/0x4000000000000000 softirq=68466/68473 fqs=2
rcu: (detected by 1, t=10502 jiffies, g=55821, q=307 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 3 Comm: pool_workqueue_ Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__lock_acquire+0x6db/0x2cf0 kernel/locking/lockdep.c:5210
Code: 5b 44 00 00 31 ed 85 c0 0f 84 6d 0d 00 00 83 3d 0a 04 a3 18 00 75 13 48 63 44 24 18 48 0f a3 05 1b 74 9f 12 0f 83 8a 1e 00 00 <49> 8b 9e 80 0b 00 00 48 83 7c 24 28 00 75 19 83 3d df 03 a3 18 00
RSP: 0018:ffffc90000007b18 EFLAGS: 00000047
RAX: 0000000000000d49 RBX: 0000000000000000 RCX: ffffffff93ec9478
RDX: 0000000000000008 RSI: ffff88801d6aaa50 RDI: ffff88801d6a9ec0
RBP: 0000000000000000 R08: ffffffff89b8abe4 R09: ffff88806a0422c0
R10: dffffc0000000000 R11: ffffffff89b8ab30 R12: ffffffffffffff03
R13: ffff88801d6aaa50 R14: ffff88801d6a9ec0 R15: ffff88801d6aaa50
FS: 0000000000000000(0000) GS:ffff88812528a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f12ed1ea540 CR3: 0000000020bf7000 CR4: 0000000000350ef0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
spin_lock include/linux/spinlock.h:342 [inline]
advance_sched+0xb4/0xc20 net/sched/sch_taprio.c:930
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:preempt_schedule_irq+0x48/0xa0 kernel/sched/core.c:7513
Code: 49 be 00 00 00 00 00 fc ff df eb 09 48 f7 03 10 00 00 00 74 53 bf 01 00 00 00 e8 73 9e e9 f5 e8 ce b5 23 f6 fb bf 01 00 00 00 53 a2 ff ff 9c 58 fa a9 00 02 00 00 74 05 e8 94 b7 23 f6 bf 01
RSP: 0018:ffffc90000087b70 EFLAGS: 00000206
RAX: 0000000000036287 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8dfab61d RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff9030c6f7 R09: 1ffffffff20618de
R10: dffffc0000000000 R11: fffffbfff20618df R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lockdep_unregister_key+0x2d5/0x350 kernel/locking/lockdep.c:6616
Code: 11 0a 09 00 89 c6 48 c7 c7 30 b8 41 96 e8 c3 cc 09 0a 90 e9 65 fe ff ff e8 38 0b 07 0a 41 f7 c7 00 02 00 00 74 b3 fb 40 84 ed <75> b2 eb c3 90 0f 0b 90 e9 26 ff ff ff 90 0f 0b 90 e9 2e ff ff ff
RSP: 0018:ffffc90000087c90 EFLAGS: 00000246
RAX: 0000000000000046 RBX: ffff888031c81930 RCX: 0000000000000046
RDX: ffffffff93fd3398 RSI: ffffffff8dfc54e9 RDI: ffffffff8c28b0e0
RBP: ffff88801d6a9e00 R08: ffffffff81af2f28 R09: ffffffff8e95cde0
R10: dffffc0000000000 R11: fffff52000010f8d R12: 0000000000000000
R13: ffff888031c81931 R14: 0000000000001000 R15: 0000000000000a47
wq_unregister_lockdep kernel/workqueue.c:4941 [inline]
pwq_release_workfn+0x6d1/0x8c0 kernel/workqueue.c:5237
kthread_worker_fn+0x4ee/0xb20 kernel/kthread.c:1025
kthread+0x389/0x470 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: rcu_preempt kthread starved for 10490 jiffies! g55821 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:27520 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x389/0x470 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: 1 UID: 0 PID: 14725 Comm: syz.6.1738 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfd4/0x13d0 kernel/smp.c:892
Code: 89 ee 83 e6 01 31 ff e8 7a 06 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 25 02 0c 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 0a 02 0c 00 eb e5 44 89
RSP: 0018:ffffc90004eb7780 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8880b873c148 RCX: 0000000000080000
RDX: ffffc9001ef82000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90004eb78b0 R08: ffffffff9030c6f7 R09: 1ffffffff20618de
R10: dffffc0000000000 R11: fffffbfff20618df R12: 1ffff110170c8589
R13: dffffc0000000000 R14: ffff8880b8642c48 R15: 0000000000000000
FS: 00007f5c4f4ae6c0(0000) GS:ffff88812538a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5c4e585b00 CR3: 0000000084f12000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
kill_bdev block/bdev.c:90 [inline]
set_blocksize+0x2c4/0x440 block/bdev.c:207
sb_set_blocksize+0xf8/0x240 block/bdev.c:240
ext4_load_super fs/ext4/super.c:5199 [inline]
__ext4_fill_super fs/ext4/super.c:5354 [inline]
ext4_fill_super+0x1e20/0x6330 fs/ext4/super.c:5824
get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
vfs_get_tree+0x92/0x2a0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3758 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3834
do_mount fs/namespace.c:4167 [inline]
__do_sys_mount fs/namespace.c:4383 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4360
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c4e59e0ca
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f5c4f4ade58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5c4f4adee0 RCX: 00007f5c4e59e0ca
RDX: 0000200000000400 RSI: 0000200000000340 RDI: 00007f5c4f4adea0
RBP: 0000200000000400 R08: 00007f5c4f4adee0 R09: 000000000021c91c
R10: 000000000021c91c R11: 0000000000000246 R12: 0000200000000340
R13: 00007f5c4f4adea0 R14: 0000000000000519 R15: 0000200000000440