rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3759/1:b..l P3858/1:b..l P3874/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=404685, q=693 ncpus=1)
task:syz.9.11002 state:R running task stack:23160 pid:3874 tgid:3874 ppid:28576 task_flags:0x40064c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x20 kernel/kcov.c:320
Code: 0c 24 89 f2 89 fe bf 05 00 00 00 e9 2a fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 48 89 f2 48 89 fe bf 07 00 00 00 e9 f8 fd
RSP: 0018:ffffc90003fb7150 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000093547 RCX: ffffffff828188aa
RDX: ffff88801f795c40 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88801d300000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000010e0285 R14: 0000000000000000 R15: 0000000003bc02a9
page_ext_invalid mm/page_ext.c:249 [inline]
lookup_page_ext+0x9f/0x100 mm/page_ext.c:265
page_ext_iter_begin include/linux/page_ext.h:133 [inline]
__update_page_owner_free_handle.isra.0+0xa4/0x4d0 mm/page_owner.c:284
__reset_page_owner+0x93/0x190 mm/page_owner.c:321
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
free_unref_folios+0xa0d/0x16f0 mm/page_alloc.c:3004
folios_put_refs+0x571/0xa90 mm/swap.c:1008
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x3f3/0xc40 mm/shmem.c:1407
evict+0x3c2/0xad0 fs/inode.c:841
iput_final fs/inode.c:1960 [inline]
iput.part.0+0x605/0xf50 fs/inode.c:2009
iput+0x35/0x40 fs/inode.c:1975
dentry_unlink_inode+0x2c0/0x4c0 fs/dcache.c:476
__dentry_kill+0x1d0/0x690 fs/dcache.c:718
finish_dput+0x76/0x480 fs/dcache.c:927
dput.part.0+0x456/0x570 fs/dcache.c:976
dput+0x1f/0x30 fs/dcache.c:968
__fput+0x519/0xb50 fs/file_table.c:518
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d2/0x2a60 kernel/exit.c:975
do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
get_signal+0x1ec7/0x21e0 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline]
irqentry_exit+0x403/0x790 kernel/entry/common.c:162
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x73756c0000
RSP: 002b:000000000000000a EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f7c18e15fa0 RCX: 00007f7c18b9c819
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46
RBP: 00007f7c18c32c91 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7c18e16038 R14: 00007f7c18e15fa0 R15: 00007ffd23080488
task:syz.9.10999 state:R running task stack:23144 pid:3858 tgid:3858 ppid:28576 task_flags:0x40064c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7369
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
_raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:198
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
lruvec_unlock_irqrestore include/linux/memcontrol.h:1492 [inline]
folios_put_refs+0x4df/0xa90 mm/swap.c:1000
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x3f3/0xc40 mm/shmem.c:1407
evict+0x3c2/0xad0 fs/inode.c:841
iput_final fs/inode.c:1960 [inline]
iput.part.0+0x605/0xf50 fs/inode.c:2009
iput+0x35/0x40 fs/inode.c:1975
dentry_unlink_inode+0x2c0/0x4c0 fs/dcache.c:476
__dentry_kill+0x1d0/0x690 fs/dcache.c:718
finish_dput+0x76/0x480 fs/dcache.c:927
dput.part.0+0x456/0x570 fs/dcache.c:976
dput+0x1f/0x30 fs/dcache.c:968
__fput+0x519/0xb50 fs/file_table.c:518
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d2/0x2a60 kernel/exit.c:975
do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
get_signal+0x1ec7/0x21e0 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline]
irqentry_exit+0x403/0x790 kernel/entry/common.c:162
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0xf000
RSP: 002b:000000000000000a EFLAGS: 00010282
RAX: 0000000000000003 RBX: 00007f7c18e15fa0 RCX: 00007f7c18b9c819
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b4a
RBP: 00007f7c18c32c91 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7c18e16038 R14: 00007f7c18e15fa0 R15: 00007ffd23080488
task:syz.7.10963 state:R running task stack:22552 pid:3759 tgid:3759 ppid:23851 task_flags:0x40064c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_is_watching+0x0/0xc0 kernel/rcu/tree.c:748
Code: 3a ff ff ff 48 89 df e8 2e 5e 88 00 eb 81 e8 57 5e 88 00 e9 49 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 53 65 ff 05 e3 b3 26 12 e8 5e ec aa 09 48 c7 c3 a8
RSP: 0018:ffffc90003cf7148 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 00000000000447e7 RCX: 1ffff11027fe1e22
RDX: 0000000000000001 RSI: ffffffff8281835a RDI: ffff88813ff0f110
RBP: ffff88801c400000 R08: 0000000000000006 R09: 0000000000001000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: 00000000010e0285 R14: 0000000000000000 R15: 0000000003bc02a9
rcu_read_lock_held_common kernel/rcu/update.c:109 [inline]
rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349
lookup_page_ext+0x6e/0x100 mm/page_ext.c:258
page_ext_iter_begin include/linux/page_ext.h:133 [inline]
__update_page_owner_free_handle.isra.0+0xa4/0x4d0 mm/page_owner.c:284
__reset_page_owner+0x93/0x190 mm/page_owner.c:321
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
free_unref_folios+0xa0d/0x16f0 mm/page_alloc.c:3004
folios_put_refs+0x571/0xa90 mm/swap.c:1008
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x3f3/0xc40 mm/shmem.c:1407
evict+0x3c2/0xad0 fs/inode.c:841
iput_final fs/inode.c:1960 [inline]
iput.part.0+0x605/0xf50 fs/inode.c:2009
iput+0x35/0x40 fs/inode.c:1975
dentry_unlink_inode+0x2c0/0x4c0 fs/dcache.c:476
__dentry_kill+0x1d0/0x690 fs/dcache.c:718
finish_dput+0x76/0x480 fs/dcache.c:927
dput.part.0+0x456/0x570 fs/dcache.c:976
dput+0x1f/0x30 fs/dcache.c:968
__fput+0x519/0xb50 fs/file_table.c:518
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d2/0x2a60 kernel/exit.c:975
do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
get_signal+0x1ec7/0x21e0 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline]
irqentry_exit+0x403/0x790 kernel/entry/common.c:162
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x1000
RSP: 002b:000000000000000a EFLAGS: 00010282
RAX: 0000000000000003 RBX: 00007fc1ca215fa0 RCX: 00007fc1c9f9c819
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46
RBP: 00007fc1ca032c91 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc1ca216038 R14: 00007fc1ca215fa0 R15: 00007fffeaa10698
rcu: rcu_preempt kthread starved for 4649 jiffies! g404685 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:27752 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7282
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 3428 Comm: kworker/R-bat_e Tainted: P L syzkaller #0 PREEMPT(full)
Tainted: [P]=PROPRIETARY_MODULE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319
Code: 00 00 8b 44 24 04 eb b2 89 44 24 04 e8 a9 fa ff ff 8b 44 24 04 eb aa 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 8b 05 22 4d 44 05 85 c0 74 20 8b 05 a0 7f 44 05 85 c0
RSP: 0018:ffffc900000064e0 EFLAGS: 00000287
RAX: ffffc90000008001 RBX: ffffc90000006f40 RCX: ffffffff921c0b01
RDX: ffffc90000006f48 RSI: ffffc90000006f10 RDI: ffffc90000006568
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000096f15 R12: ffffc900000065a8
R13: ffffc90000006558 R14: ffffc90000006f40 R15: ffffc9000000658c
FS: 0000000000000000(0000) GS:ffff8881242e2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f88d0fc5fd7 CR3: 0000000078f14000 CR4: 00000000003526f0
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:867 [inline]
class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0x3a8/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 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:2689 [inline]
slab_free mm/slub.c:6246 [inline]
kmem_cache_free+0x127/0x6c0 mm/slub.c:6373
__skb_ext_put+0x102/0x2f0 net/core/skbuff.c:7223
skb_ext_reset include/linux/skbuff.h:5116 [inline]
skb_ext_reset include/linux/skbuff.h:5113 [inline]
skb_scrub_packet+0x377/0x430 net/core/skbuff.c:6243
____dev_forward_skb include/linux/netdevice.h:4409 [inline]
__dev_forward_skb2+0x38a/0x740 net/core/dev.c:2440
veth_forward_skb drivers/net/veth.c:323 [inline]
veth_xmit+0x2c2/0xee0 drivers/net/veth.c:379
__netdev_start_xmit include/linux/netdevice.h:5343 [inline]
netdev_start_xmit include/linux/netdevice.h:5352 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x128/0x7a0 net/core/dev.c:3904
__dev_queue_xmit+0x1baa/0x4950 net/core/dev.c:4870
dev_queue_xmit include/linux/netdevice.h:3401 [inline]
br_dev_queue_push_xmit+0x361/0x530 net/bridge/br_forward.c:53
br_nf_dev_queue_xmit+0x73b/0x2730 net/bridge/br_netfilter_hooks.c:914
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
br_nf_post_routing+0xcbb/0x16a0 net/bridge/br_netfilter_hooks.c:960
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK include/linux/netfilter.h:316 [inline]
br_forward_finish+0x261/0x4d0 net/bridge/br_forward.c:66
br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1161
br_nf_forward_finish+0x693/0xb30 net/bridge/br_netfilter_hooks.c:663
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
br_nf_forward_ip.part.0+0x61e/0x820 net/bridge/br_netfilter_hooks.c:717
br_nf_forward_ip net/bridge/br_netfilter_hooks.c:677 [inline]
br_nf_forward+0xfe5/0x19f0 net/bridge/br_netfilter_hooks.c:774
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK include/linux/netfilter.h:316 [inline]
__br_forward+0x2f7/0x970 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
br_flood+0x37f/0x650 net/bridge/br_forward.c:250
br_handle_frame_finish+0xff4/0x1f60 net/bridge/br_input.c:229
br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1161
br_nf_pre_routing_finish_ipv6+0x659/0xdd0 net/bridge/br_netfilter_ipv6.c:153
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:183
br_nf_pre_routing+0x90f/0x1560 net/bridge/br_netfilter_hooks.c:509
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0xcdd/0x1520 net/bridge/br_input.c:442
__netif_receive_skb_core.constprop.0+0x6c5/0x3530 net/core/dev.c:6096
__netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6207
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6322
process_backlog+0x37a/0x1580 net/core/dev.c:6673
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7737
napi_poll net/core/dev.c:7800 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7957
handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
__batadv_dat_purge.part.0+0x294/0x3c0 net/batman-adv/distributed-arp-table.c:185
__batadv_dat_purge net/batman-adv/distributed-arp-table.c:166 [inline]
batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:204
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3609
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245