rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5615/1:b..l rcu: (detected by 1, t=10502 jiffies, g=29489, q=415 ncpus=2) task:syz-executor state:R running task stack:23320 pid:5615 tgid:5615 ppid:5603 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] copy_pte_range mm/memory.c:1347 [inline] copy_pmd_range mm/memory.c:1408 [inline] copy_pud_range mm/memory.c:1445 [inline] copy_p4d_range mm/memory.c:1469 [inline] copy_page_range+0x1c1f/0x5b20 mm/memory.c:1555 dup_mmap+0xd44/0x21b0 mm/mmap.c:1840 dup_mm kernel/fork.c:1543 [inline] copy_mm kernel/fork.c:1595 [inline] copy_process+0x4588/0x8030 kernel/fork.c:2289 kernel_clone+0x176/0x9d0 kernel/fork.c:2748 __do_sys_clone+0xd9/0x120 kernel/fork.c:2889 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8d3f7c68d2 RSP: 002b:00007ffdd0d70830 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffdd0d70830 RCX: 00007f8d3f7c68d2 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffdd0d709bc R08: 0000000000000000 R09: 0000000000000001 R10: 000055556157c7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 000000000004313f R15: 00007ffdd0d70a10 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g29489 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=12326 rcu: rcu_preempt kthread starved for 10502 jiffies! g29489 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:27672 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: 8149 Comm: syz.4.683 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:107 [inline] RIP: 0010:raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2170 [inline] RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1302 [inline] RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] RIP: 0010:do_raw_spin_lock+0x128/0x260 kernel/locking/spinlock_debug.c:116 Code: 0f 84 06 01 00 00 48 89 df be 04 00 00 00 c7 44 24 28 00 00 00 00 e8 87 9a 94 00 be 04 00 00 00 48 8d 7c 24 28 e8 78 9a 94 00 <8b> 44 24 28 ba 01 00 00 00 89 44 24 04 f0 0f b1 13 0f 85 93 00 00 RSP: 0018:ffffc90000007cb8 EFLAGS: 00000097 RAX: 0000000000000001 RBX: ffffffff9b9d1180 RCX: ffffffff81e5b2e8 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007ce0 RBP: ffffffff9b9d1188 R08: 0000000000000001 R09: fffff52000000f9c R10: 0000000000000003 R11: 0000000000000000 R12: 1ffff92000000f98 R13: ffffffff9b9d1190 R14: 0000000000000001 R15: 1ffff92000000fb2 FS: 00007fa3640976c0(0000) GS:ffff888123dee000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa364096ff8 CR3: 00000000242db000 CR4: 00000000003526f0 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:166 debug_object_activate+0x144/0x4b0 lib/debugobjects.c:873 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline] debug_activate kernel/time/hrtimer.c:528 [inline] enqueue_hrtimer+0x75/0x2f0 kernel/time/hrtimer.c:1109 __run_hrtimer kernel/time/hrtimer.c:2048 [inline] __hrtimer_run_queues+0x6ed/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 16 df 29 f6 48 89 df e8 9e 2e 2a f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 95 3f 19 f6 65 8b 05 ee 98 a7 08 85 c0 74 16 5b RSP: 0018:ffffc9000420fb10 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff888056b9c898 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e1a25e5 RDI: ffffffff8c400c80 RBP: 0000000000000283 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000 R13: 368c60fa9c419204 R14: 18befbfa9c417a94 R15: ffff888056b9c898 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] timerfd_clock_was_set+0x164/0x310 fs/timerfd.c:115 clock_was_set+0x652/0x850 kernel/time/hrtimer.c:1004 do_adjtimex+0x302/0x370 kernel/time/timekeeping.c:3006 do_clock_adjtime kernel/time/posix-timers.c:1169 [inline] __do_sys_clock_adjtime+0x177/0x290 kernel/time/posix-timers.c:1181 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa36319de59 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:00007fa364097028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007fa363426090 RCX: 00007fa36319de59 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000000 RBP: 00007fa363233e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa363426128 R14: 00007fa363426090 R15: 00007ffeb6ec8108