rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6184/1:b.el
rcu: (detected by 0, t=11548 jiffies, g=14961, q=618 ncpus=2)
task:syz-executor state:R running task stack:27448 pid:6184 tgid:6184 ppid:6001 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
wp_page_copy mm/memory.c:3653 [inline]
do_wp_page+0x1d1d/0x5800 mm/memory.c:4013
handle_pte_fault mm/memory.c:6068 [inline]
__handle_mm_fault+0x1033/0x5440 mm/memory.c:6195
handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364
do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f82b38645b2
RSP: 002b:00007ffd1c315060 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 00007f82b3a13464 RSI: 0000000000000040 RDI: 00007ffd1c3151b0
RBP: 00007ffd1c3151b0 R08: 0000000000000019 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00000000000927c0 R14: 000000000002a17a R15: 00007ffd1c315310
rcu: rcu_preempt kthread starved for 11548 jiffies! g14961 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
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+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 982 Comm: kworker/1:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_power_efficient gc_worker
RIP: 0010:div64_u64 include/linux/math64.h:69 [inline]
RIP: 0010:taprio_set_budgets+0x223/0x3b0 net/sched/sch_taprio.c:674
Code: 89 f7 e8 20 d5 87 f8 49 8b 0e 4c 89 e8 48 09 c8 48 c1 e8 20 74 0d 4c 89 e8 31 d2 48 f7 f1 49 89 c5 eb 0a 44 89 e8 31 d2 f7 f1 <41> 89 c5 bf 11 00 00 00 4c 89 e6 e8 2d 67 24 f8 49 83 fc 10 77 6c
RSP: 0018:ffffc90000a08c00 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000190
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88807de7d2e0
RBP: 0000000000000000 R08: ffff88807de7d2e7 R09: 1ffff1100fbcfa5c
R10: dffffc0000000000 R11: ffffed100fbcfa5d R12: 0000000000000000
R13: 0000000000000000 R14: ffff88807de7d2e0 R15: ffff8880590c6000
FS: 0000000000000000(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffcfbdcbe8 CR3: 000000005d332000 CR4: 00000000003526f0
Call Trace:
advance_sched+0x963/0xc90 net/sched/sch_taprio.c:982
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 7b 41 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003997880 EFLAGS: 00000206
RAX: 036f967d90569c00 RBX: 0000000000000000 RCX: 036f967d90569c00
RDX: 0000000000000000 RSI: ffffffff8dba93b2 RDI: ffffffff8be33e80
RBP: ffffffff89ad4564 R08: 0000000000000000 R09: ffffffff89ad4564
R10: dffffc0000000000 R11: fffffbfff1f474a7 R12: 0000000000000002
R13: ffffffff8e13a0e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
gc_worker+0x285/0x1380 net/netfilter/nf_conntrack_core.c:1546
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245