rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P50/1:b..l P13457/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=64349, q=730 ncpus=2)
task:syz.2.1883 state:R running task stack:25176 pid:13457 tgid:13456 ppid:5840 task_flags:0x40054c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071
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]
zap_pte_range mm/memory.c:1884 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x38bc/0x4170 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:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f11e618f749
RSP: 002b:00007f11e7027038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: 0000000000000001 RBX: 00007f11e63e5fa0 RCX: 00007f11e618f749
RDX: 0000200000000780 RSI: 0000000000000001 RDI: 00007f11e6ffe000
RBP: 00007f11e6213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f11e63e6038 R14: 00007f11e63e5fa0 R15: 00007ffdf826d038
task:kworker/u8:3 state:R running task stack:21080 pid:50 tgid:50 ppid:2 task_flags:0x4208160 flags:0x00080000
Workqueue: bat_events batadv_mcast_mla_update
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:67
Code: b3 00 48 ba 00 00 00 00 00 fc ff df e9 88 fc ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 23 d2 9b ff cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000bb7318 EFLAGS: 00000202
RAX: ffffc90000bb7f38 RBX: ffffc90000bb0000 RCX: 0000000000000001
RDX: ffffc90000bb7488 RSI: dffffc0000000000 RDI: ffffc90000bb7e30
RBP: 1ffff92000176e89 R08: ffffc90000bb7e30 R09: ffffc90000bb7498
R10: dffffc0000000000 R11: fffff52000176e95 R12: 1ffff92000176e8a
R13: 1ffff92000176e8b R14: ffffc90000bb8000 R15: dffffc0000000000
deref_stack_reg+0x19f/0x230 arch/x86/kernel/unwind_orc.c:422
unwind_next_frame+0x18cc/0x23d0 arch/x86/kernel/unwind_orc.c:-1
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6668 [inline]
kfree+0x1c0/0x660 mm/slub.c:6876
batadv_mcast_mla_list_free net/batman-adv/multicast.c:667 [inline]
__batadv_mcast_mla_update net/batman-adv/multicast.c:924 [inline]
batadv_mcast_mla_update+0x3398/0x3640 net/batman-adv/multicast.c:946
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
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: rcu_preempt kthread starved for 10495 jiffies! g64349 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:27280 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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: 1 UID: 0 PID: 0 Comm: swapper/1 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:sched_core_balance+0x15f/0xf40 kernel/sched/core.c:6284
Code: 0b 00 4c 89 b4 24 80 00 00 00 4c 89 7c 24 60 e9 73 0d 00 00 4c 89 f7 e8 ef 27 cb 09 e8 0a 53 36 00 fb 48 8b 9c 24 88 00 00 00 <83> fb 08 0f 83 3b 0d 00 00 4c 8d 24 dd d0 2d 9b 8d 4c 89 e0 48 c1
RSP: 0018:ffffc900001979c0 EFLAGS: 00000282
RAX: 8850579b4a2fd900 RBX: 0000000000000001 RCX: 8850579b4a2fd900
RDX: 0000000000000000 RSI: ffffffff8d7925c0 RDI: ffffffff8bc08360
RBP: ffffc90000197b48 R08: ffffffff8f822077 R09: 1ffffffff1f0440e
R10: dffffc0000000000 R11: fffffbfff1f0440f R12: ffff8880b873a900
R13: dffffc0000000000 R14: ffff8880b873a900 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34d10ff8 CR3: 0000000077e9f000 CR4: 0000000000350ef0
Call Trace:
do_balance_callbacks kernel/sched/core.c:4901 [inline]
__balance_callbacks kernel/sched/core.c:4955 [inline]
finish_lock_switch kernel/sched/core.c:4994 [inline]
finish_task_switch+0x404/0x940 kernel/sched/core.c:5112
context_switch kernel/sched/core.c:5259 [inline]
__schedule+0x14c4/0x5000 kernel/sched/core.c:6863
schedule_idle+0x52/0x90 kernel/sched/core.c:6986
do_idle+0x4b3/0x520 kernel/sched/idle.c:360
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147