rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12845/1:b..l P12853/1:b..l rcu: (detected by 1, t=10503 jiffies, g=181045, q=1883 ncpus=2) task:syz.1.10736 state:R running task stack:25336 pid:12853 tgid:12841 ppid:7563 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3d0 kernel/locking/lockdep.c:5893 Code: 57 7a 11 00 00 00 00 eb b5 e8 25 b4 0b 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 a5 11 7a 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 8a 9a 0e 0a cc 48 8d 3d d2 2e 73 RSP: 0018:ffffc90012c17540 EFLAGS: 00000282 RAX: 40ae418a4a953000 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000002 RSI: ffffffff8e163366 RDI: ffffffff8c27aa00 RBP: ffff88801d7529a8 R08: ffffc90012c178b0 R09: 0000000000000000 R10: ffffc90012c17698 R11: fffff52002582ed5 R12: 0000000000000002 R13: 0000000000000002 R14: ffffffff8e7602e0 R15: ffff88801d751e40 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695 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:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __slab_free+0x263/0x2b0 mm/slub.c:5532 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:406 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5219 [inline] __kmalloc_noprof+0x35c/0x760 mm/slub.c:5231 kmalloc_noprof include/linux/slab.h:966 [inline] kzalloc_noprof include/linux/slab.h:1200 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x246/0x630 security/tomoyo/file.c:728 security_file_ioctl+0xc3/0x2a0 security/security.c:2435 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a2039c799 RSP: 002b:00007f4a21221028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4a20616180 RCX: 00007f4a2039c799 RDX: 0000200000000000 RSI: 00000000000089a2 RDI: 0000000000000009 RBP: 00007f4a20432bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4a20616218 R14: 00007f4a20616180 R15: 00007ffca1d178e8 task:syz.0.10737 state:R running task stack:25152 pid:12845 tgid:12845 ppid:8121 task_flags:0x40004c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872 Code: e9 30 ff ff ff e8 65 e5 0b 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 e1 42 7a 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 c6 cb 0e 0a cc 48 8d 3d 9e 5c 73 RSP: 0018:ffffc900126474c0 EFLAGS: 00000296 RAX: 758417fdae1ba300 RBX: 0000000000000246 RCX: 0000000000000046 RDX: 000000004cfe2b93 RSI: ffffffff8e163366 RDI: ffffffff8c27aa00 RBP: 0000000000000000 R08: ffffffff823be48a R09: ffffffff8e7602e0 R10: dffffc0000000000 R11: ffffed10069ff24c R12: 0000000000000002 R13: ffffffff8e7602e0 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] __page_table_check_zero+0x87/0x3e0 mm/page_table_check.c:138 page_table_check_free include/linux/page_table_check.h:46 [inline] __free_pages_prepare mm/page_alloc.c:1434 [inline] free_unref_folios+0xeee/0x16d0 mm/page_alloc.c:3040 folios_put_refs+0x789/0x8d0 mm/swap.c:1002 free_pages_and_swap_cache+0x2e7/0x5b0 mm/swap_state.c:423 __tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline] tlb_batch_pages_flush mm/mmu_gather.c:151 [inline] tlb_flush_mmu_free mm/mmu_gather.c:398 [inline] tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:405 tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:530 exit_mmap+0x498/0xa10 mm/mmap.c:1315 __mmput+0x118/0x430 kernel/fork.c:1174 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x62e/0x2320 kernel/exit.c:959 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 __do_sys_exit_group kernel/exit.c:1123 [inline] __se_sys_exit_group kernel/exit.c:1121 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7b7e59c799 RSP: 002b:00007ffd3c4bf228 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b7e59c799 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd3c4bf28c R08: 0000000000000000 R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000000ec R13: 00000000000927c0 R14: 00000000000f6093 R15: 00007ffd3c4bf2e0 rcu: rcu_preempt kthread starved for 1614 jiffies! g181045 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:28128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 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+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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: 1 UID: 0 PID: 1298 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:879 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1193 [inline] RIP: 0010:unwind_next_frame+0x1a66/0x23c0 arch/x86/kernel/unwind_orc.c:695 Code: 50 4c 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 35 02 00 00 41 c7 06 00 00 00 00 31 db e8 03 d4 36 0a 85 c0 74 3a e8 6a 11 34 00 <84> c0 75 31 e8 f1 d3 36 0a 85 c0 74 28 80 3d c7 c3 84 0e 00 75 1f RSP: 0018:ffffc90000a07278 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff91051c01 RCX: 0000000080000302 RDX: ffffc90000a07301 RSI: ffffffff8c27a9e0 RDI: ffffffff8c27a9a0 RBP: dffffc0000000000 R08: ffffc9000528fe18 R09: 0000000000000000 R10: ffffc90000a07398 R11: fffff52000140e75 R12: ffffc9000528fe28 R13: ffffc90005288000 R14: ffffc90000a07348 R15: ffffffff81767a45 FS: 0000000000000000(0000) GS:ffff888125564000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4213270731 CR3: 000000000e54c000 CR4: 00000000003526f0 Call Trace: 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:2687 [inline] slab_free mm/slub.c:6124 [inline] kmem_cache_free+0x187/0x630 mm/slub.c:6254 dev_kfree_skb_any include/linux/netdevice.h:4197 [inline] team_dummy_transmit+0x1a/0x30 drivers/net/team/team_core.c:502 team_xmit+0x25b/0x3d0 drivers/net/team/team_core.c:1687 __netdev_start_xmit include/linux/netdevice.h:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3871 [inline] dev_hard_start_xmit+0x2d8/0x870 net/core/dev.c:3887 __dev_queue_xmit+0x16d1/0x3890 net/core/dev.c:4840 dev_queue_xmit include/linux/netdevice.h:3384 [inline] br_dev_queue_push_xmit+0x370/0x4a0 net/bridge/br_forward.c:53 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_post_routing+0xb66/0xfe0 net/bridge/br_netfilter_hooks.c:966 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1167 [inline] br_nf_forward_finish+0xa5e/0xe90 net/bridge/br_netfilter_hooks.c:662 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318 br_nf_forward_ip+0x7ef/0xa30 net/bridge/br_netfilter_hooks.c:716 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 br_handle_frame_finish+0x1492/0x1b40 net/bridge/br_input.c:229 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x31a0 net/core/dev.c:6054 __netif_receive_skb_one_core net/core/dev.c:6165 [inline] __netif_receive_skb net/core/dev.c:6280 [inline] process_backlog+0x76d/0x1950 net/core/dev.c:6631 __napi_poll+0xae/0x340 net/core/dev.c:7695 napi_poll net/core/dev.c:7758 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7910 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline] __dev_queue_xmit+0x1e78/0x3890 net/core/dev.c:4876 dev_queue_xmit include/linux/netdevice.h:3384 [inline] tx+0x6b/0x190 drivers/block/aoe/aoenet.c:62 kthread+0x1e0/0x3f0 drivers/block/aoe/aoecmd.c:1241 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245