rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7380/2:b..l rcu: (detected by 1, t=10502 jiffies, g=21633, q=1226 ncpus=2) task:syz.0.272 state:R running task stack:26200 pid:7380 tgid:7375 ppid:5877 task_flags:0x400040 flags:0x20004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 7b 41 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9001c526cd8 EFLAGS: 00000206 RAX: 6a2bf1e456642800 RBX: 0000000000000000 RCX: 6a2bf1e456642800 RDX: 0000000000000000 RSI: ffffffff8dba93b2 RDI: ffffffff8be33e80 RBP: ffffffff8172d195 R08: 0000000000000000 R09: ffffffff8172d195 R10: ffffc9001c526e98 R11: ffffffff81ac4b00 R12: 0000000000000002 R13: ffffffff8e13a0e0 R14: 0000000000000000 R15: 0000000000000246 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:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 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:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 __folio_put+0x21b/0x2c0 mm/swap.c:112 folio_put_refs include/linux/mm.h:1380 [inline] __collapse_huge_page_copy_succeeded mm/khugepaged.c:747 [inline] __collapse_huge_page_copy mm/khugepaged.c:829 [inline] collapse_huge_page mm/khugepaged.c:1231 [inline] hpage_collapse_scan_pmd+0x2af7/0x3c60 mm/khugepaged.c:1436 madvise_collapse+0x3d1/0xa40 mm/khugepaged.c:2813 madvise_vma_behavior+0xec8/0x3af0 mm/madvise.c:1358 madvise_walk_vmas+0x51c/0xa30 mm/madvise.c:1669 madvise_do_behavior+0x38e/0x550 mm/madvise.c:1885 do_madvise+0x1bc/0x270 mm/madvise.c:1978 __do_sys_madvise mm/madvise.c:1987 [inline] __se_sys_madvise mm/madvise.c:1985 [inline] __ia32_sys_madvise+0xa7/0xc0 mm/madvise.c:1985 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf70de539 RSP: 002b:00000000f506955c EFLAGS: 00000206 ORIG_RAX: 00000000000000db RAX: ffffffffffffffda RBX: 0000000080000000 RCX: 0000000000600003 RDX: 0000000000000019 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10523 jiffies! g21633 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=12680 rcu: rcu_preempt kthread starved for 10529 jiffies! g21633 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 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+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 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: 7379 Comm: syz.0.272 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x70 kernel/kcov.c:217 Code: 24 65 48 8b 0c 25 08 b0 a0 92 65 8b 15 b8 f2 e0 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c <8b> 91 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 RSP: 0018:ffffc9001c5170d8 EFLAGS: 00000246 RAX: ffffffff8a226a14 RBX: 000000000e000000 RCX: ffff888027213c00 RDX: 0000000000000000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9001c517230 R08: 0000000000000000 R09: ffffffff8a226780 R10: dffffc0000000000 R11: fffff520038a2e0c R12: dffffc0000000000 R13: ffff88805c2aaa80 R14: 0000000000000000 R15: ffffc9001c5176a0 FS: 0000000000000000(0000) GS:ffff888125c15000(0063) knlGS:00000000f548cb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000801e8018 CR3: 00000000776a8000 CR4: 00000000003526f0 Call Trace: xfrm_state_lookup_spi_proto net/xfrm/xfrm_state.c:1707 [inline] xfrm_alloc_spi+0x534/0xf30 net/xfrm/xfrm_state.c:2589 xfrm_alloc_userspi+0x70b/0xc90 net/xfrm/xfrm_user.c:1873 xfrm_user_rcv_msg+0x7a0/0xab0 net/xfrm/xfrm_user.c:3501 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg+0x164/0x220 net/socket.c:2700 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf70de539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f548c55c EFLAGS: 00000206 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000080000080 RDX: 0000000000004810 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000