rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11019/1:b..l rcu: (detected by 0, t=10506 jiffies, g=58321, q=509 ncpus=2) task:syz.7.1305 state:R running task stack:25320 pid:11019 tgid:11017 ppid:9028 task_flags:0x40044c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5893 Code: 06 9e 11 00 00 00 00 eb b5 e8 05 36 14 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 f5 c0 9d 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 5a 26 17 0a cc 48 8d 3d 32 a4 94 RSP: 0018:ffffc900063d6e50 EFLAGS: 00000286 RAX: 3a40dd46ad946300 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000001 RSI: ffffffff8e247e65 RDI: ffffffff8c2892e0 RBP: ffff888032de4938 R08: ffffffff823bdf62 R09: ffffffff8e95cce0 R10: dffffc0000000000 R11: fffff9400033f437 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8e95cce0 R15: ffff888032de3d80 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] page_ext_put+0xa3/0xc0 mm/page_ext.c:579 __reset_page_owner+0x67/0x1f0 mm/page_owner.c:312 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xcec/0x1480 mm/page_alloc.c:2996 folios_put_refs+0x789/0x8d0 mm/swap.c:1002 free_pages_and_swap_cache+0x41d/0x490 mm/swap_state.c:404 __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:417 [inline] tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:424 zap_pte_range mm/memory.c:1957 [inline] zap_pmd_range mm/memory.c:2004 [inline] zap_pud_range mm/memory.c:2032 [inline] zap_p4d_range mm/memory.c:2053 [inline] __zap_vma_range+0x3dc3/0x4b40 mm/memory.c:2093 unmap_vmas+0x379/0x530 mm/memory.c:2162 exit_mmap+0x280/0x9e0 mm/mmap.c:1300 __mmput+0x118/0x430 kernel/fork.c:1178 exit_mm+0x18e/0x250 kernel/exit.c:581 do_exit+0x6a2/0x22c0 kernel/exit.c:963 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc1c4d9c819 RSP: 002b:00007fc1c5c2b028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007fc1c5016090 RCX: 00007fc1c4d9c819 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007fc1c4e32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc1c5016128 R14: 00007fc1c5016090 R15: 00007fc1c513fa48 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g58321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=23331 rcu: rcu_preempt kthread starved for 10506 jiffies! g58321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27400 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 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: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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11040 Comm: syz.8.1310 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__lock_acquire+0xd2/0x2cf0 kernel/locking/lockdep.c:5138 Code: e8 f3 f0 ff ff 48 85 c0 0f 84 76 13 00 00 49 89 d9 8b 0d c1 53 a9 18 48 8b 54 24 08 8b 92 88 0b 00 00 85 c9 0f 94 c1 83 fa 30 <40> 0f 93 c6 40 20 ce 40 80 fe 01 0f 84 21 01 00 00 8b 9c 24 40 01 RSP: 0018:ffffc90000a08b40 EFLAGS: 00000083 RAX: ffffffff93e88370 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffffffff9a6a9a60 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffffff9a6a9a60 R10: dffffc0000000000 R11: fffff520001411ac R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 FS: 00007f7434eff6c0(0000) GS:ffff888125325000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7433fe9f00 CR3: 0000000074a7e000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 debug_object_activate+0x83/0x580 lib/debugobjects.c:835 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline] debug_activate kernel/time/hrtimer.c:528 [inline] enqueue_hrtimer+0xa9/0x2c0 kernel/time/hrtimer.c:1109 __run_hrtimer kernel/time/hrtimer.c:1946 [inline] __hrtimer_run_queues+0x4d2/0xa20 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061 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:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 7d 94 e9 f5 f7 c3 00 02 00 00 74 05 e8 40 1d 15 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 c4 16 db f5 65 8b 05 0d e3 86 07 85 c0 74 18 5b 41 5e c3 cc cc RSP: 0018:ffffc90006476ee8 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000282 RCX: 0000000080000202 RDX: 0000000000000002 RSI: ffffffff8dfd1e21 RDI: 0000000000000001 RBP: ffffc900064771d0 R08: ffffffff903338f7 R09: 1ffffffff206671e R10: dffffc0000000000 R11: fffffbfff206671f R12: ffff88802ab5a290 R13: dffffc0000000000 R14: ffff88802ab5a2a8 R15: ffff88802ab5a2f8 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] taprio_change+0x30fe/0x3e50 net/sched/sch_taprio.c:1985 taprio_init+0x96f/0xbe0 net/sched/sch_taprio.c:2124 qdisc_create+0x7c4/0xf20 net/sched/sch_api.c:1319 __tc_modify_qdisc net/sched/sch_api.c:1753 [inline] tc_modify_qdisc+0x16f0/0x2290 net/sched/sch_api.c:1817 rtnetlink_rcv_msg+0x77e/0xbe0 net/core/rtnetlink.c:7003 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 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: 0033:0x7f7433f9c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7434eff028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7434216090 RCX: 00007f7433f9c819 RDX: 0000000000000010 RSI: 00002000000012c0 RDI: 0000000000000006 RBP: 00007f7434032c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7434216128 R14: 00007f7434216090 R15: 00007f743433fa48