rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5611/1:b..l P23785/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=203917, q=1935 ncpus=2)
task:syz.6.4781 state:R running task stack:24392 pid:23785 tgid:23763 ppid:22894 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__kasan_check_byte+0x2d/0x40 mm/kasan/common.c:578
Code: d6 41 56 53 48 89 f3 49 89 fe e8 3e 15 00 00 84 c0 75 16 be 01 00 00 00 4c 89 f7 31 d2 48 89 d9 89 c3 e8 f6 04 00 00 89 d8 5b <41> 5e c3 cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90
RSP: 0018:ffffc90004fa68e8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8176f273 RDI: 1ffffffff1d2b9bc
RBP: ffffffff8176f256 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90004fa6ab8 R11: ffffffff81b0efc0 R12: 0000000000000002
R13: ffffffff8e95cde0 R14: ffffffff8e95cde0 R15: 0000000000000000
kasan_check_byte include/linux/kasan.h:402 [inline]
lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5842
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
__free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
__slab_free+0x274/0x2c0 mm/slub.c:5612
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4569 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905
__kernfs_new_node+0xea/0x970 fs/kernfs/dir.c:664
kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:748
__kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057
sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313
create_files fs/sysfs/group.c:82 [inline]
internal_create_group+0x673/0x1180 fs/sysfs/group.c:189
internal_create_groups fs/sysfs/group.c:229 [inline]
sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:255
device_add_groups drivers/base/core.c:2837 [inline]
device_add_attrs+0x1bf/0x5b0 drivers/base/core.c:2912
device_add+0x496/0xbb0 drivers/base/core.c:3645
netdev_register_kobject+0x178/0x310 net/core/net-sysfs.c:2343
register_netdevice+0x1456/0x1ec0 net/core/dev.c:11423
__ip_tunnel_create+0x3e8/0x560 net/ipv4/ip_tunnel.c:268
ip_tunnel_init_net+0x2e7/0x840 net/ipv4/ip_tunnel.c:1147
ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
setup_net+0x118/0x340 net/core/net_namespace.c:446
copy_net_ns+0x50e/0x730 net/core/net_namespace.c:579
create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:132
copy_namespaces+0x438/0x4b0 kernel/nsproxy.c:195
copy_process+0x1f49/0x4440 kernel/fork.c:2267
kernel_clone+0x284/0x8f0 kernel/fork.c:2721
__do_sys_clone kernel/fork.c:2862 [inline]
__se_sys_clone kernel/fork.c:2846 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2846
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1c4f39ce59
RSP: 002b:00007f1c4cdaffd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f1c4f616360 RCX: 00007f1c4f39ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000640c7000
RBP: 00007f1c4f432d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f1c4f6163f8 R14: 00007f1c4f616360 R15: 00007f1c4f73fa48
task:syz-executor state:R running task stack:21992 pid:5611 tgid:5611 ppid:5610 task_flags:0x400100 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_is_watching+0x67/0xb0 kernel/rcu/tree.c:753
Code: 89 f7 e8 4c 24 86 00 48 c7 c3 d8 99 3a 93 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 29 82 8e 11 <74> 11 83 e0 04 c1 e8 02 5b 41 5e 41 5f e9 87 1a 01 0a cc e8 51 bd
RSP: 0018:ffffc90003877170 EFLAGS: 00000286
RAX: 0000000000eaf924 RBX: ffff8880b86339d8 RCX: 0000000080000001
RDX: ffffc90003877301 RSI: ffffffff8c28b0c0 RDI: ffffffff8c28b080
RBP: dffffc0000000000 R08: ffffc90003877778 R09: 0000000000000000
R10: ffffc90003877318 R11: fffff5200070ee65 R12: ffffc90003877788
R13: ffffffff8176f256 R14: ffffffff8e26a790 R15: dffffc0000000000
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3c0 kernel/locking/lockdep.c:5879
rcu_lock_release include/linux/rcupdate.h:310 [inline]
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0x1bba/0x2550 arch/x86/kernel/unwind_orc.c:709
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
__free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
__slab_free+0x274/0x2c0 mm/slub.c:5612
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4569 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4950
kmalloc_reserve net/core/skbuff.c:613 [inline]
__alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713
alloc_skb_fclone include/linux/skbuff.h:1433 [inline]
tcp_stream_alloc_skb+0x3f/0x580 net/ipv4/tcp.c:935
tcp_sendmsg_locked+0x1345/0x5360 net/ipv4/tcp.c:1260
tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1455
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
sock_write_iter+0x406/0x4f0 net/socket.c:1254
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:688
ksys_write+0x150/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff400557fd7
RSP: 002b:00007ffcfa0c0180 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555568f16540 RCX: 00007ff400557fd7
RDX: 00000000000000d8 RSI: 00007ff3fdffff28 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000d8
R13: 0000555568f2af80 R14: 00007ffcfa0c0760 R15: 00007ff3fdffff28
rcu: rcu_preempt kthread starved for 694 jiffies! g203917 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:27536 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 3229 Comm: kworker/R-bat_e Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:check_preemption_disabled+0x1/0xe0 lib/smp_processor_id.c:13
Code: 80 b0 28 8c 48 c7 c6 c0 b0 28 8c eb 1c 66 66 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 55 <41> 57 41 56 53 65 8b 05 87 3f 90 07 65 8b 0d 7c 3f 90 07 f7 c1 ff
RSP: 0018:ffffc90000006de8 EFLAGS: 00000283
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c28b0c0 RDI: ffffffff8c28b080
RBP: ffffffff8176f256 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000006fd8 R11: ffffffff81b0efc0 R12: 0000000000000002
R13: ffffffff8e95cde0 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812528a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000033d030 CR3: 000000007a018000 CR4: 00000000003526f0
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:752
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/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:6250 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6377
nft_synproxy_eval_v6+0x352/0x4e0 net/netfilter/nft_synproxy.c:92
nft_synproxy_do_eval+0x3ce/0x580 net/netfilter/nft_synproxy.c:146
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1ae0 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6202 [inline]
__netif_receive_skb net/core/dev.c:6315 [inline]
process_backlog+0x7dd/0x1950 net/core/dev.c:6666
__napi_poll+0xae/0x340 net/core/dev.c:7733
napi_poll net/core/dev.c:7796 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7953
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:815 [inline]
batadv_iv_ogm_schedule+0x27b/0xf50 net/batman-adv/bat_iv_ogm.c:869
batadv_iv_send_outstanding_bat_ogm_packet+0x68d/0x7a0 net/batman-adv/bat_iv_ogm.c:1747
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
rescuer_thread+0x827/0x1130 kernel/workqueue.c:3621
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245