rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5835/1:b..l P5197/1:b..l rcu: (detected by 1, t=10502 jiffies, g=15413, q=266 ncpus=2) task:udevd state:R running task stack:23776 pid:5197 tgid:5197 ppid:1 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:127 sock_def_readable+0x1fb/0x550 net/core/sock.c:3551 __netlink_sendskb net/netlink/af_netlink.c:1265 [inline] netlink_sendskb+0xa1/0x140 net/netlink/af_netlink.c:1271 netlink_unicast+0x397/0x9e0 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x830 net/socket.c:2630 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684 __sys_sendmsg net/socket.c:2716 [inline] __do_sys_sendmsg net/socket.c:2721 [inline] __se_sys_sendmsg net/socket.c:2719 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fec155e3407 RSP: 002b:00007ffec25ac1f0 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fec15557880 RCX: 00007fec155e3407 RDX: 0000000000000000 RSI: 00007ffec25ac250 RDI: 0000000000000004 RBP: 000055ac54101660 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b4 R13: 000055ac540f99e0 R14: 0000000000000000 R15: 0000000000000000 task:syz-executor state:R running task stack:21672 pid:5835 tgid:5835 ppid:5827 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1329 [inline] copy_pmd_range+0x7630/0x7f00 mm/memory.c:1389 copy_pud_range mm/memory.c:1426 [inline] copy_p4d_range mm/memory.c:1450 [inline] copy_page_range+0xc14/0x1270 mm/memory.c:1538 dup_mmap+0xf4c/0x1b10 mm/mmap.c:1834 dup_mm kernel/fork.c:1489 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1541 copy_process+0x1706/0x3c00 kernel/fork.c:2181 kernel_clone+0x21e/0x840 kernel/fork.c:2609 __do_sys_clone kernel/fork.c:2750 [inline] __se_sys_clone kernel/fork.c:2734 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3085985713 RSP: 002b:00007fff2092c3c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3085985713 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055558e7087d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000002d73e R15: 00007fff2092c560 rcu: rcu_preempt kthread timer wakeup didn't happen for 10498 jiffies! g15413 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=7369 rcu: rcu_preempt kthread starved for 10499 jiffies! g15413 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 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+0x4bc/0x870 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6880 Comm: syz.0.227 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline] RIP: 0010:lock_acquire+0x94/0x360 kernel/locking/lockdep.c:5844 Code: 0f 84 d7 01 00 00 83 3d 89 b3 00 0e 00 0f 84 f0 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 c3 3b 88 00 83 3d 6c b3 00 0e 00 <0f> 84 fa 00 00 00 65 8b 05 3f 4e f4 10 85 c0 0f 85 eb 00 00 00 65 RSP: 0018:ffffc90000007c00 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: bf6be22b53ce7c00 RDX: 0000000000000000 RSI: ffffffff8b505582 RDI: 1ffff110170c4f5b RBP: ffffffff81ade7b2 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1f3c2af R12: 0000000000000000 R13: ffff8880b8627ad8 R14: 0000000000000000 R15: 0000000000000001 FS: 00007f1ed6ba66c0(0000) GS:ffff888125d06000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1ed6ba5f98 CR3: 0000000011711000 CR4: 0000000000350ef0 Call Trace: __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1781 [inline] __hrtimer_run_queues+0x602/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 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+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 bb ab 77 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 53 da 3f f6 65 8b 05 dc 48 41 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc9001e637b60 EFLAGS: 00000206 RAX: bf6be22b53ce7c00 RBX: 0000000000000216 RCX: bf6be22b53ce7c00 RDX: 0000000000000007 RSI: ffffffff8d7eb243 RDI: 0000000000000001 RBP: ffffc9001e637bf0 R08: ffffffff8f9e1577 R09: 1ffffffff1f3c2ae R10: dffffc0000000000 R11: fffffbfff1f3c2af R12: dffffc0000000000 R13: ffff8880b8627ac0 R14: ffff8880b8627ac0 R15: 1ffff92003cc6f6c clock_was_set+0x63b/0x7c0 kernel/time/hrtimer.c:965 do_settimeofday64+0x3cb/0x5a0 kernel/time/timekeeping.c:1460 __do_sys_clock_settime kernel/time/posix-timers.c:1131 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1115 [inline] __x64_sys_clock_settime+0x24f/0x290 kernel/time/posix-timers.c:1115 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1ed5d8efc9 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:00007f1ed6ba6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f1ed5fe5fa0 RCX: 00007f1ed5d8efc9 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f1ed5e11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ed5fe6038 R14: 00007f1ed5fe5fa0 R15: 00007ffe97cdbc78