rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4395/1:b..l P8216/1:b..l
(detected by 0, t=10502 jiffies, g=39905, q=28 ncpus=2)
task:syz.4.1084 state:R running task stack:22864 pid:8216 ppid:4280 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6562
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6731
preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6755
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
unwind_next_frame+0x172b/0x1fd0 arch/x86/kernel/unwind_orc.c:629
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
save_stack+0x121/0x230 mm/page_owner.c:127
__reset_page_owner+0x51/0x190 mm/page_owner.c:148
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1487 [inline]
free_pcp_prepare mm/page_alloc.c:1537 [inline]
free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414
free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3555
release_pages+0x20d1/0x2340 mm/swap.c:1035
__pagevec_release+0x6d/0xe0 mm/swap.c:1055
pagevec_release include/linux/pagevec.h:71 [inline]
folio_batch_release include/linux/pagevec.h:135 [inline]
shmem_undo_range+0x808/0x21d0 mm/shmem.c:946
shmem_truncate_range mm/shmem.c:1062 [inline]
shmem_evict_inode+0x225/0x9f0 mm/shmem.c:1171
evict+0x4b6/0x8b0 fs/inode.c:705
__dentry_kill+0x412/0x630 fs/dcache.c:611
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xfa/0x1d0 fs/dcache.c:918
__fput+0x597/0x8b0 fs/file_table.c:328
task_work_run+0x1d0/0x260 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x9d5/0x2570 kernel/exit.c:881
do_group_exit+0x229/0x2e0 kernel/exit.c:1024
get_signal+0x1259/0x1340 kernel/signal.c:2872
arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316
exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1485
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7ff52719de99
RSP: 002b:00007ff52804efd8 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 00007ff527425fa0 RCX: 00007ff52719de99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000400
RBP: 00007ff527233eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ff527426038 R14: 00007ff527425fa0 R15: 00007ffeffa468e8
task:kworker/u4:13 state:R running task stack:23984 pid:4395 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6562
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5680
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc900045ffac0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: d8814f3bc2d1f000
RDX: 0000000000000000 RSI: ffffffff8a8c2920 RDI: ffffffff8adf42e0
RBP: ffffc900045ffbc8 R08: dffffc0000000000 R09: 1ffffffff2162048
R10: dffffc0000000000 R11: fffffbfff2162049 R12: 0000000000000000
R13: 1ffff920008bff64 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xeb/0x600 net/batman-adv/network-coding.c:719
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: rcu_preempt kthread starved for 10567 jiffies! g39905 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:26384 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 67 01 99 f7 e9 44 ff ff ff e8 8d 03 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d f7 60 4c 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffffff8c807d88 EFLAGS: 000002c6
RAX: ff46adfef9101800 RBX: ffffffff8a3a4b17 RCX: ff46adfef9101800
RDX: 0000000000000001 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf42e0
RBP: ffffffff8c807ec0 R08: ffff8880b8e3580b R09: 1ffff110171c6b01
R10: dffffc0000000000 R11: ffffed10171c6b02 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8c8bc740 R15: 1ffffffff1900fbc
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000007a86a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
default_idle_call+0x84/0xc0 kernel/sched/idle.c:109
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x3a2/0x680 kernel/sched/idle.c:323
cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:422
rest_init+0x2dc/0x300 init/main.c:745
arch_call_rest_init+0xa/0xa init/main.c:904
start_kernel+0x493/0x53c init/main.c:1151
secondary_startup_64_no_verify+0xcf/0xdb