rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5824/1:b..l rcu: (detected by 1, t=10502 jiffies, g=43385, q=196 ncpus=2) task:syz-executor state:R running task stack:21152 pid:5824 tgid:5824 ppid:5817 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline] RIP: 0010:lock_release+0x5a/0x3b0 kernel/locking/lockdep.c:5881 Code: 10 83 f8 08 0f 83 57 02 00 00 89 c0 48 0f a3 05 4c 04 e4 0d 73 0d e8 a5 dd 08 00 84 c0 0f 84 95 02 00 00 83 3d 66 34 e4 0d 00 <0f> 84 1d 02 00 00 65 8b 05 69 36 e2 10 85 c0 0f 85 0e 02 00 00 65 RSP: 0018:ffffc90002ff71d0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff901a6701 RCX: 0000000080000001 RDX: ffffc90002ff7301 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300 RBP: dffffc0000000000 R08: ffffc90002ff7430 R09: ffffc90002ff7358 R10: dffffc0000000000 R11: fffff520005fee6d R12: ffffc90002ff7440 R13: ffffffff8173fd65 R14: ffffffff8df41aa0 R15: ffffffff8173fd65 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 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:1406 [inline] free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:3000 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x1490 mm/shmem.c:1137 shmem_truncate_range mm/shmem.c:1249 [inline] shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1379 evict+0x5f4/0xae0 fs/inode.c:837 do_unlinkat+0x340/0x560 fs/namei.c:5443 __do_sys_unlink fs/namei.c:5474 [inline] __se_sys_unlink fs/namei.c:5472 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:5472 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe52538ecf7 RSP: 002b:00007ffdf0c7f598 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe52538ecf7 RDX: 00007ffdf0c7f5c0 RSI: 00007ffdf0c7f650 RDI: 00007ffdf0c7f650 RBP: 00007ffdf0c7f650 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffdf0c806e0 R13: 00007fe525413d7d R14: 000000000008d162 R15: 00007ffdf0c80720 rcu: rcu_preempt kthread starved for 10547 jiffies! g43385 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:27648 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 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: 1 UID: 0 PID: 11839 Comm: syz.7.1680 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:taprio_dequeue_tc_priority+0x26f/0x750 net/sched/sch_taprio.c:798 Code: 00 00 41 8b 5d 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 39 02 00 00 45 8b 36 89 df 44 89 f6 e8 b4 93 50 f8 44 39 f3 <73> 15 48 8b 5c 24 10 48 85 db 0f 85 7a 04 00 00 e8 dc 91 50 f8 eb RSP: 0018:ffffc90000a08cd8 EFLAGS: 00000283 RAX: ffffffff897065cc RBX: 0000000000000008 RCX: 0000000000000100 RDX: ffff888044ba5b80 RSI: 0000000000000010 RDI: 0000000000000008 RBP: 1ffff1100a8f706a R08: ffffffff896fbf46 R09: ffffffff8df41aa0 R10: 0000000000000001 R11: ffffffff896302e0 R12: dffffc0000000000 R13: ffff8880547b8354 R14: 0000000000000010 R15: 0000000000000002 FS: 00007fe5dad766c0(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000003c030 CR3: 0000000028430000 CR4: 0000000000350ef0 Call Trace: taprio_dequeue+0x186/0x550 net/sched/sch_taprio.c:-1 dequeue_skb net/sched/sch_generic.c:297 [inline] qdisc_restart net/sched/sch_generic.c:402 [inline] __qdisc_run+0x23f/0x1510 net/sched/sch_generic.c:420 qdisc_run+0xc7/0x300 include/net/pkt_sched.h:120 net_tx_action+0x717/0x900 net/core/dev.c:5783 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x60/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:194 Code: f7 e8 cd 4a 42 f6 f7 c3 00 02 00 00 74 05 e8 20 77 6c f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 04 65 34 f6 65 8b 05 0d c8 23 07 85 c0 74 18 5b 41 5e e9 dc f8 RSP: 0018:ffffc9000f0cf5f0 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000212 RCX: 0000000080000001 RDX: 0000000000000006 RSI: ffffffff8d79227f RDI: 0000000000000001 RBP: ffff888031b23280 R08: ffffffff8f822377 R09: 1ffffffff1f0446e R10: dffffc0000000000 R11: fffffbfff1f0446f R12: dffffc0000000000 R13: 1ffff1100a3ff8ed R14: ffff888051ffc700 R15: 0000000000000212 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __skb_try_recv_datagram+0x17c/0x4d0 net/core/datagram.c:267 __unix_dgram_recvmsg+0x2d4/0xd60 net/unix/af_unix.c:2576 sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1078 ____sys_recvmsg+0x3aa/0x460 net/socket.c:2810 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2854 do_recvmmsg+0x307/0x770 net/socket.c:2949 __sys_recvmmsg net/socket.c:3023 [inline] __do_sys_recvmmsg net/socket.c:3046 [inline] __se_sys_recvmmsg net/socket.c:3039 [inline] __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3039 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe5d9f8f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe5dad76038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fe5da1e5fa0 RCX: 00007fe5d9f8f749 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fe5da013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe5da1e6038 R14: 00007fe5da1e5fa0 R15: 00007ffc0e7b70c8