rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=b4b/1/0x4000000000000000 softirq=14983/14986 fqs=3 (detected by 0, t=10502 jiffies, g=18797, q=50) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6697 Comm: syz-executor.3 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1176 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x62/0x150 kernel/rcu/tree.c:1167 Code: c5 0f 87 f5 00 00 00 48 8d 3c ed a0 38 58 8b 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 ad 00 00 00 <48> 03 1c ed a0 38 58 8b 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 18 RSP: 0018:ffffc90000dc0e18 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 000000000003ab40 RCX: 0000000000000000 RDX: 1ffffffff16b0715 RSI: 0000000000010003 RDI: ffffffff8b5838a8 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff8167060d R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880b9d2a740 R14: ffff8880b9d2a640 R15: 0000000000000001 FS: 00007fca05722700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007249e000 CR4: 0000000000350ee0 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_held_common kernel/rcu/update.c:102 [inline] rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:123 trace_hrtimer_expire_exit include/trace/events/timer.h:279 [inline] __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0xa2e/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:finish_task_switch.isra.0+0x323/0xb80 kernel/sched/core.c:4866 Code: 73 4f fa 07 85 c0 75 02 0f 0b 48 85 db 0f 85 25 01 00 00 4c 89 f7 e8 fc f7 ff ff e8 77 6b 2d 00 fb 65 48 8b 1c 25 40 70 02 00 <48> 8d bb 80 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc9000b4e7858 EFLAGS: 00000206 RAX: 0000000000000d2b RBX: ffff88801a843a00 RCX: 1ffffffff1ff832e RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000b4e78a0 R08: 0000000000000001 R09: ffffffff8ffb9a17 R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880b9d3a9d8 R13: ffff88807baa5700 R14: ffff8880b9d39c80 R15: ffff8880b9d3a6b8 context_switch kernel/sched/core.c:4989 [inline] __schedule+0xaba/0x4f00 kernel/sched/core.c:6296 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6711 irqentry_exit+0x31/0x80 kernel/entry/common.c:425 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5607 Code: d7 a5 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc9000b4e7ab8 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200169cf59 RCX: 0000000000000001 RDX: 1ffff1100350888b RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000185408 R09: 0000000000000001 R10: fffffbfff2028598 R11: 1ffffffff1f0ec51 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8bcac2a0 R15: 0000000000000000 __fs_reclaim_acquire mm/page_alloc.c:4535 [inline] fs_reclaim_acquire+0x115/0x160 mm/page_alloc.c:4549 might_alloc include/linux/sched/mm.h:227 [inline] slab_pre_alloc_hook mm/slab.h:711 [inline] slab_alloc_node mm/slub.c:3144 [inline] slab_alloc mm/slub.c:3238 [inline] __kmalloc+0x58/0x340 mm/slub.c:4420 kmalloc include/linux/slab.h:587 [inline] kzalloc include/linux/slab.h:716 [inline] lsm_superblock_alloc security/security.c:691 [inline] security_sb_alloc+0x101/0x240 security/security.c:894 alloc_super+0x1e5/0xac0 fs/super.c:231 sget+0x10b/0x580 fs/super.c:616 mount_bdev+0xf8/0x410 fs/super.c:1343 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1500 do_new_mount fs/namespace.c:2994 [inline] path_mount+0x1320/0x1fa0 fs/namespace.c:3324 do_mount fs/namespace.c:3337 [inline] __do_sys_mount fs/namespace.c:3545 [inline] __se_sys_mount fs/namespace.c:3522 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3522 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fca06dae3ea Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fca05721f88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000180 RCX: 00007fca06dae3ea RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fca05721fe0 RBP: 00007fca05722020 R08: 00007fca05722020 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000 R13: 0000000020000100 R14: 00007fca05721fe0 R15: 0000000020000200 rcu: rcu_preempt kthread starved for 10496 jiffies! g18797 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:28736 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4f00 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 4184 Comm: kworker/u4:7 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:458 print_other_cpu_stall kernel/rcu/tree_stall.h:563 [inline] check_cpu_stall kernel/rcu/tree_stall.h:706 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq+0x1f7c/0x2150 kernel/rcu/tree.c:2617 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:969 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 60 7c 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31 RSP: 0018:ffffc90003f0f9f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9d3e9e0 RCX: 0000000000000000 RDX: ffff888023608000 RSI: ffffffff816c2410 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816c2436 R11: 0000000000000000 R12: ffffed10173a7d3d R13: 0000000000000001 R14: ffff8880b9d3e9e8 R15: 0000000000000001 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1112 [inline] text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1297 text_poke_flush arch/x86/kernel/alternative.c:1451 [inline] text_poke_flush arch/x86/kernel/alternative.c:1448 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1458 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1da/0x400 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:734 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:726 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 0f 87 f5 00 00 00 ja 0xfb 6: 48 8d 3c ed a0 38 58 lea -0x74a7c760(,%rbp,8),%rdi d: 8b e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 15: fc ff df 18: 48 89 fa mov %rdi,%rdx 1b: 48 c1 ea 03 shr $0x3,%rdx 1f: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 23: 0f 85 ad 00 00 00 jne 0xd6 * 29: 48 03 1c ed a0 38 58 add -0x74a7c760(,%rbp,8),%rbx <-- trapping instruction 30: 8b 31: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 38: fc ff df 3b: 48 8d 7b 18 lea 0x18(%rbx),%rdi