rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (2 ticks this GP) idle=088c/1/0x4000000000000000 softirq=100218/100218 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18050/1:b..l rcu: (detected by 0, t=10504 jiffies, g=110737, q=1263 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17734 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:kasan_check_range+0x9/0x2c0 mm/kasan/generic.c:199 Code: c6 45 24 4b 8e e8 97 39 f4 fe 90 0f 0b cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 41 57 41 56 <41> 55 41 54 53 b0 01 48 85 f6 0f 84 ae 01 00 00 4c 8d 04 37 49 39 RSP: 0018:ffffc90000a08cb0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff9a9d4f48 RCX: ffffffff81a2ca4d RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9a9d4f48 RBP: ffff888039b22cf8 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000141190 R12: dffffc0000000000 R13: ffff888039b22ce8 R14: ffffffff9a9d4f4c R15: 1ffff1100736459f FS: 0000555580b08500(0000) GS:ffff888125054000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f51b53ef4b8 CR3: 0000000033a00000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read include/linux/instrumented.h:82 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline] debug_spin_unlock kernel/locking/spinlock_debug.c:101 [inline] do_raw_spin_unlock+0x4d/0x210 kernel/locking/spinlock_debug.c:141 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:177 [inline] _raw_spin_unlock_irqrestore+0x23/0x80 kernel/locking/spinlock.c:198 debug_object_activate+0x2ec/0x420 lib/debugobjects.c:891 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:2048 [inline] __hrtimer_run_queues+0x4ce/0xa10 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:unwind_next_frame+0x48e/0x2550 arch/x86/kernel/unwind_orc.c:520 Code: d8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 b4 19 00 00 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 bf 19 00 00 0f b6 43 01 <83> e0 07 0f 84 7c 16 00 00 83 f8 01 4c 8b 6c 24 50 49 bc 00 00 00 RSP: 0018:ffffc9001990f840 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffffff91835860 RCX: ffffffff90d3f158 RDX: ffffffff9183585c RSI: ffffffff9183585c RDI: ffffffff8c4bda20 RBP: ffffffff8a75d299 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000 R13: ffffffff91835861 R14: ffffc9001990f8e8 R15: ffffffff90d3f158 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4959 sk_prot_alloc+0x57/0x210 net/core/sock.c:2246 sk_alloc+0x3a/0x390 net/core/sock.c:2308 inet6_create+0x81a/0x1270 net/ipv6/af_inet6.c:178 __sock_create+0x4b3/0x9d0 net/socket.c:1651 sock_create net/socket.c:1709 [inline] __sys_socket_create net/socket.c:1746 [inline] __sys_socket+0xd6/0x1b0 net/socket.c:1793 __do_sys_socket net/socket.c:1807 [inline] __se_sys_socket net/socket.c:1805 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1805 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f51b519f707 Code: f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 b8 29 00 00 00 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:00007fffb4470b38 EFLAGS: 00000202 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f51b519f707 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 000000000000000a RBP: 00007fffb447126c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007f51b53ebe00 R13: 00000000000927c0 R14: 000000000008ea23 R15: 00007f51b53edfc0 task:kworker/1:45 state:R running task stack:23688 pid:18050 tgid:18050 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:gc_worker+0x3b2/0x1890 net/netfilter/nf_conntrack_core.c:1540 Code: 9e d5 f7 44 3b 74 24 5c 0f 83 09 0e 00 00 44 89 f0 4c 8d 34 c3 4c 89 f0 48 c1 e8 03 48 bb 00 00 00 00 00 fc ff df 80 3c 18 00 <74> 08 4c 89 f7 e8 14 28 43 f8 4d 8b 3e 4c 89 fe 48 83 e6 01 31 ff RSP: 0018:ffffc9000371f9a0 EFLAGS: 00000246 RAX: 1ffff1100490d4c0 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffff888039583e00 RSI: 0000000000040000 RDI: 000000000000d4c0 RBP: ffffc9000371faf0 R08: ffffffff905784f7 R09: 1ffffffff20af09e R10: dffffc0000000000 R11: fffffbfff20af09f R12: 1ffff1100eec1439 R13: ffff88807760a1c8 R14: ffff88802486a600 R15: 000000000000d4c0 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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: rcu_preempt kthread starved for 6962 jiffies! g110737 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 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: CPU: 0 UID: 0 PID: 16473 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x10b0/0x14b0 kernel/smp.c:892 Code: c0 75 73 41 8b 1e 89 de 83 e6 01 31 ff e8 d8 22 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 84 1e 0c 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 69 1e 0c RSP: 0018:ffffc90003baf460 EFLAGS: 00000293 RAX: ffffffff81ba5317 RBX: dffffc0000000000 RCX: ffff88802751be00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003baf588 R08: ffffffff905784f7 R09: 1ffffffff20af09e R10: dffffc0000000000 R11: fffffbfff20af09f R12: 1ffff110170e81d1 R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124f54000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86a7f60700 CR3: 000000000e946000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x5c4/0x1090 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline] tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423 tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:549 free_ldt_pgtables+0x192/0x360 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:229 [inline] exit_mmap+0x1bf/0x9f0 mm/mmap.c:1285 __mmput+0x118/0x420 kernel/fork.c:1187 exit_mm+0x221/0x2d0 kernel/exit.c:615 do_exit+0x6cd/0x2360 kernel/exit.c:997 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 get_signal+0x121b/0x12c0 kernel/signal.c:3046 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __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:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efe2e359017 Code: Unable to access opcode bytes at 0x7efe2e358fed. RSP: 002b:00007ffdab0c1800 EFLAGS: 00000202 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 00005555636ba500 RCX: 00007efe2e359017 RDX: 0000000040000000 RSI: 00007ffdab0c185c RDI: ffffffffffffffff RBP: 00007ffdab0c185c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffdab0c1ab8 R15: 0000000000000000