rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...0: (1 GPs behind) idle=8b04/1/0x4000000000000000 softirq=148067/148071 fqs=1747
rcu: hardirqs softirqs csw/system
rcu: number: 0 0 0
rcu: cputime: 0 0 0 ==> 52490(ms)
rcu: (detected by 0, t=10502 jiffies, g=186877, q=1596 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 21929 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_acquire+0x219/0x420 kernel/locking/lockdep.c:5758
Code: 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 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 <65> 48 8b 04 25 28 00 00 00 48 3b 84 24 c0 00 00 00 0f 85 f9 00 00
RSP: 0018:ffffc900001f0b00 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: f809ff059c4ffd00
RDX: 0000000000000000 RSI: ffffffff8acadd60 RDI: ffffffff8b1d0660
RBP: ffffc900001f0c08 R08: dffffc0000000000 R09: 1ffffffff223d6a0
R10: dffffc0000000000 R11: fffffbfff223d6a1 R12: 1ffff9200003e16c
R13: ffffffff974f7fb0 R14: 0000000000000046 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5cdf2a8ff8 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
debug_object_activate+0x6c/0x500 lib/debugobjects.c:747
debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline]
debug_activate kernel/time/hrtimer.c:504 [inline]
enqueue_hrtimer+0x34/0x380 kernel/time/hrtimer.c:1100
__run_hrtimer kernel/time/hrtimer.c:1771 [inline]
__hrtimer_run_queues+0x62f/0xc10 kernel/time/hrtimer.c:1818
hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 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 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000323f9c0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: f809ff059c4ffd00
RDX: 0000000000000000 RSI: ffffffff8acadd60 RDI: ffffffff8b1d0660
RBP: ffffc9000323fae0 R08: dffffc0000000000 R09: 1ffffffff223d6a0
R10: dffffc0000000000 R11: fffffbfff223d6a1 R12: 1ffff92000647f44
R13: ffffffff8d131da0 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
batadv_nc_process_nc_paths+0xdb/0x380 net/batman-adv/network-coding.c:687
batadv_nc_worker+0x423/0x600 net/batman-adv/network-coding.c:728
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: rcu_preempt kthread starved for 1755 jiffies! g186877 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:26856 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 12540 Comm: kworker/0:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events drain_vmap_area_work
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xd85/0x1190 kernel/smp.c:855
Code: 45 8b 34 24 44 89 f6 83 e6 01 31 ff e8 14 fe 0a 00 41 83 e6 01 49 be 00 00 00 00 00 fc ff df 75 07 e8 4f fa 0a 00 eb 38 f3 90 <42> 0f b6 04 33 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 33 fa
RSP: 0018:ffffc90003e3f8a0 EFLAGS: 00000293
RAX: ffffffff817c7a9d RBX: 1ffff110171e82bd RCX: ffff888019f41e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003e3fa20 R08: ffffffff911eb50f R09: 1ffffffff223d6a1
R10: dffffc0000000000 R11: fffffbfff223d6a2 R12: ffff8880b8f415e8
R13: ffff8880b8e3d3c0 R14: dffffc0000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6ecfff37b0 CR3: 00000000192fc000 CR4: 00000000003506f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
__purge_vmap_area_lazy+0x223/0x1ab0 mm/vmalloc.c:1757
drain_vmap_area_work+0x40/0xd0 mm/vmalloc.c:1812
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293