rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5803/1:b..l P7565/1:b..l P6016/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=51741, q=522 ncpus=2)
task:kworker/u8:18 state:R running task stack:22744 pid:6016 tgid:6016 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872
Code: b4 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 22 bd ee 0e 0f 82 74 02 00 00 8b 35 ba ed ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 b4 18 12 0f 85 ad 02 00 00 48 83 c4
RSP: 0018:ffffc9000479f608 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 000000001a1c5929
RDX: 0000000000000000 RSI: ffffffff8daa80f3 RDI: ffffffff8bf2b380
RBP: 0000000000000002 R08: 00000000875f66eb R09: 00000000b875f66e
R10: 0000000000000002 R11: ffff88803266aff0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xd1/0x20b0 arch/x86/kernel/unwind_orc.c:495
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6670 [inline]
kfree+0x2f8/0x6e0 mm/slub.c:6878
batadv_iv_send_outstanding_bat_ogm_packet+0x26d/0x920 net/batman-adv/bat_iv_ogm.c:1715
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:kworker/u8:21 state:R running task stack:24088 pid:7565 tgid:7565 ppid:2 task_flags:0x24248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_notrace+0x62/0xe0 kernel/sched/core.c:7140
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x8e/0xc0 kernel/rcu/tree.c:752
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x2cd/0x330 kernel/locking/lockdep.c:5831
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline]
percpu_ref_put include/linux/percpu-refcount.h:351 [inline]
blk_mq_dispatch_list+0x563/0x1300 block/blk-mq.c:2943
blk_mq_flush_plug_list block/blk-mq.c:2987 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2959
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1225
blk_flush_plug include/linux/blkdev.h:1205 [inline]
io_schedule_prepare kernel/sched/core.c:7758 [inline]
io_schedule+0xba/0x130 kernel/sched/core.c:7788
rq_qos_wait+0x22f/0x340 block/blk-rq-qos.c:307
__wbt_wait block/blk-wbt.c:596 [inline]
wbt_wait+0x1b8/0x3a0 block/blk-wbt.c:656
__rq_qos_throttle+0x56/0xa0 block/blk-rq-qos.c:66
rq_qos_throttle block/blk-rq-qos.h:168 [inline]
rq_qos_throttle block/blk-rq-qos.h:163 [inline]
blk_mq_get_new_requests block/blk-mq.c:3053 [inline]
blk_mq_submit_bio+0x22c9/0x2c50 block/blk-mq.c:3204
__submit_bio+0x3cc/0x690 block/blk-core.c:637
__submit_bio_noacct_mq block/blk-core.c:724 [inline]
submit_bio_noacct_nocheck+0x53d/0xbe0 block/blk-core.c:755
submit_bio_noacct+0x5bd/0x1f40 block/blk-core.c:879
ext4_io_submit fs/ext4/page-io.c:404 [inline]
io_submit_add_bh fs/ext4/page-io.c:445 [inline]
ext4_bio_write_folio+0x756/0x1dc0 fs/ext4/page-io.c:589
mpage_process_page_bufs+0x47c/0x8d0 fs/ext4/inode.c:2198
mpage_prepare_extent_to_map+0x750/0x1510 fs/ext4/inode.c:2737
ext4_do_writepages+0xa11/0x3c80 fs/ext4/inode.c:2878
ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3026
do_writepages+0x27a/0x600 mm/page-writeback.c:2598
__writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737
writeback_sb_inodes+0x72e/0x1ce0 fs/fs-writeback.c:2030
__writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2107
wb_writeback+0x799/0xae0 fs/fs-writeback.c:2218
wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
wb_do_writeback fs/fs-writeback.c:2375 [inline]
wb_workfn+0x8a0/0xbb0 fs/fs-writeback.c:2403
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:syz-executor state:R running task stack:25800 pid:5803 tgid:5803 ppid:5798 task_flags:0x40050c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7047
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+0x3e/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+0x1047/0x43c0 mm/memory.c:2017
unmap_single_vma+0x153/0x240 mm/memory.c:2059
unmap_vmas+0x218/0x470 mm/memory.c:2101
exit_mmap+0x1b0/0xb60 mm/mmap.c:1277
__mmput+0x12a/0x410 kernel/fork.c:1173
mmput+0x62/0x70 kernel/fork.c:1196
exit_mm kernel/exit.c:581 [inline]
do_exit+0x7d7/0x2bd0 kernel/exit.c:959
do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 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+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faa55985853
RSP: 002b:00007fff1ddd12b8 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 00000000000016b9 RCX: 00007faa55985853
RDX: 0000000040000000 RSI: 00007fff1ddd12cc RDI: 00000000ffffffff
RBP: 00007fff1ddd12cc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007fff1ddd15b8 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10618 jiffies! g51741 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:28064 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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: 0 UID: 0 PID: 0 Comm: swapper/0 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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: a6 5f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 29 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 0000000002343105 RBX: 0000000000000000 RCX: ffffffff8b7836d9
RDX: 0000000000000000 RSI: ffffffff8dace187 RDI: ffffffff8bf2b380
RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d
R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000
R13: ffffffff8e097b40 R14: ffffffff9088b8d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49a039ef98 CR3: 0000000029a35000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3ef/0x4d0 init/main.c:1206
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148