INFO: rcu detected stall in fanotify

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7729/1:b..l P5894/1:b..l P7742/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=20297, q=2831 ncpus=2)
task:syz.2.497       state:R  running task     stack:29112 pid:7742  tgid:7729  ppid:5821   task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 4c e2 11 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 d2 d1 c7 0e 0f 82 74 02 00 00 8b 35 2a 02 c8 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 29 4c e2 11 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc9001d15fa00 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e1c4120 RCX: 00000000fd57315f
RDX: 0000000000000000 RSI: ffffffff8d7fb592 RDI: ffffffff8bd011c0
RBP: 0000000000000002 R08: 13af9f48ce65b07e R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1169 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 discard_slab mm/slub.c:3301 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3848
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:408
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 __fsnotify_alloc_group fs/notify/group.c:120 [inline]
 fsnotify_alloc_group+0x92/0x330 fs/notify/group.c:151
 __do_sys_fanotify_init+0x287/0xc00 fs/notify/fanotify/fanotify_user.c:1593
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe607f8eec9
RSP: 002b:00007fe608ead038 EFLAGS: 00000246 ORIG_RAX: 000000000000012c
RAX: ffffffffffffffda RBX: 00007fe6081e6090 RCX: 00007fe607f8eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000079
RBP: 00007fe608011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe6081e6128 R14: 00007fe6081e6090 R15: 00007ffcc6a8cba8
 </TASK>
task:kworker/0:4     state:R  running task     stack:22232 pid:5894  tgid:5894  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 4c e2 11 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 d2 d1 c7 0e 0f 82 74 02 00 00 8b 35 2a 02 c8 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 29 4c e2 11 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc90004e4eaa8 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e1c4120 RCX: 00000000c57b64e8
RDX: 0000000000000000 RSI: ffffffff8d7fb592 RDI: ffffffff8bd011c0
RBP: 0000000000000002 R08: 73f60d2b5ebb4ee2 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1169 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4946 [inline]
 slab_alloc_node mm/slub.c:5245 [inline]
 kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5252
 __kernfs_new_node+0xd2/0x8e0 fs/kernfs/dir.c:637
 kernfs_new_node+0x13c/0x1e0 fs/kernfs/dir.c:713
 __kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1057
 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:313
 create_files fs/sysfs/group.c:76 [inline]
 internal_create_group+0x578/0xf30 fs/sysfs/group.c:183
 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:223
 device_add_groups drivers/base/core.c:2836 [inline]
 device_add_attrs drivers/base/core.c:2911 [inline]
 device_add+0x77f/0x1aa0 drivers/base/core.c:3643
 usb_create_ep_devs+0x160/0x2b0 drivers/usb/core/endpoint.c:170
 create_intf_ep_devs.isra.0+0x161/0x200 drivers/usb/core/message.c:1252
 usb_set_configuration+0x11a7/0x1e20 drivers/usb/core/message.c:2216
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x3e0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:581 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:659
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:801
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:959
 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1aa0 drivers/base/core.c:3689
 usb_new_device+0xd07/0x1a60 drivers/usb/core/hub.c:2694
 hub_port_connect drivers/usb/core/hub.c:5566 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 port_event drivers/usb/core/hub.c:5870 [inline]
 hub_event+0x2f34/0x4fe0 drivers/usb/core/hub.c:5952
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:syz.2.497       state:R  running task     stack:25960 pid:7729  tgid:7729  ppid:5821   task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 4c e2 11 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 d2 d1 c7 0e 0f 82 74 02 00 00 8b 35 2a 02 c8 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 29 4c e2 11 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc9001d1af258 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e1c4120 RCX: 00000000afca01de
RDX: 0000000000000000 RSI: ffffffff8d7fb592 RDI: ffffffff8bd011c0
RBP: 0000000000000002 R08: b19b3a4d46fadd4d R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1169 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 discard_slab mm/slub.c:3301 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3848
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4946 [inline]
 slab_alloc_node mm/slub.c:5245 [inline]
 kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5252
 mt_alloc_one lib/maple_tree.c:172 [inline]
 mas_alloc_nodes lib/maple_tree.c:1108 [inline]
 mas_preallocate+0xe6a/0x11f0 lib/maple_tree.c:5192
 vma_iter_prealloc mm/vma.h:442 [inline]
 __split_vma+0x34a/0x1070 mm/vma.c:528
 split_vma mm/vma.c:598 [inline]
 vma_modify+0xee1/0x2030 mm/vma.c:1631
 vma_modify_flags+0x212/0x2d0 mm/vma.c:1649
 mprotect_fixup+0x1df/0xb40 mm/mprotect.c:816
 do_mprotect_pkey+0x9bc/0xd40 mm/mprotect.c:990
 __do_sys_mprotect mm/mprotect.c:1011 [inline]
 __se_sys_mprotect mm/mprotect.c:1008 [inline]
 __x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:1008
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe607f8ef87
RSP: 002b:00007ffcc6a8cb48 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007fe608e8c6c0 RCX: 00007fe607f8ef87
RDX: 0000000000000003 RSI: 0000000000020000 RDI: 00007fe608e6d000
RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000021000 R11: 0000000000000206 R12: 00007ffcc6a8cca0
R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 7355 jiffies! g20297 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27704 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 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+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:124 [inline]
RIP: 0010:lock_release+0x68/0x2f0 kernel/locking/lockdep.c:5881
Code: 0f a3 05 8b d8 c7 0e 0f 82 b1 01 00 00 8b 3d e3 08 c8 0e 85 ff 0f 84 25 01 00 00 65 8b 05 a8 94 e2 11 85 c0 0f 85 16 01 00 00 <65> 4c 8b 35 e8 52 e2 11 41 8b b6 2c 0b 00 00 85 f6 0f 85 ff 00 00
RSP: 0018:ffffc90000a07f20 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8e1c4120 RCX: ffffc90000a09001
RDX: 0000000000000000 RSI: ffffffff8bd01140 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000006160 R12: ffffffff816a98f4
R13: ffffc90000a08028 R14: ffffc90000a080c8 R15: ffffc90000a0805c
FS:  0000000000000000(0000) GS:ffff888124f85000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc3e9f3ed8 CR3: 00000000321a2000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1169 [inline]
 unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479
 __unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758
 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:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:342 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:368
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4946 [inline]
 slab_alloc_node mm/slub.c:5245 [inline]
 kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5297
 kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:579
 __alloc_skb+0x166/0x380 net/core/skbuff.c:670
 alloc_skb include/linux/skbuff.h:1383 [inline]
 synproxy_send_client_synack+0x1af/0x8f0 net/netfilter/nf_synproxy_core.c:460
 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline]
 nft_synproxy_do_eval+0xa63/0xd80 net/netfilter/nft_synproxy.c:141
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x2e9/0x1920 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
 nf_hook.constprop.0+0x424/0x750 include/linux/netfilter.h:273
 NF_HOOK include/linux/netfilter.h:316 [inline]
 ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:260
 dst_input include/net/dst.h:474 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:453 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:573
 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6079
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6192
 process_backlog+0x439/0x15e0 net/core/dev.c:6544
 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7594
 napi_poll net/core/dev.c:7657 [inline]
 net_rx_action+0x97f/0xef0 net/core/dev.c:7784
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: ae 60 02 e9 d3 09 03 00 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 2e 1e 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6
RAX: 0000000001bc8331 RBX: 0000000000000001 RCX: ffffffff8b4bda89
RDX: 0000000000000000 RSI: ffffffff8d820d97 RDI: ffffffff8bd011c0
RBP: ffffed1003bd5490 R08: 0000000000000001 R09: ffffed10170e6655
R10: ffff8880b87332ab R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801deaa480 R14: ffffffff905f3590 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x38d/0x500 kernel/sched/idle.c:330
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x148
 </TASK>
hrtimer: interrupt took 2342240228 ns