rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=acd/1/0x4000000000000000 softirq=145404/145404 fqs=3 (detected by 0, t=10502 jiffies, g=239521, q=85) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 24801 Comm: syz-executor.1 Tainted: G S 5.18.0-rc3-syzkaller-00080-gd569e86915b7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline] RIP: 0010:lock_is_held_type+0xe4/0x140 kernel/locking/lockdep.c:5685 Code: f6 47 22 03 0f 95 c0 45 31 ed 44 39 f0 41 0f 94 c5 48 c7 c7 a0 5c cc 89 e8 89 0d 00 00 b8 ff ff ff ff 65 0f c1 05 24 b9 98 76 <83> f8 01 75 29 9c 58 f6 c4 02 75 3d 48 f7 04 24 00 02 00 00 74 01 RSP: 0018:ffffc90000de0e00 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000010001 RDI: 0000000000000000 RBP: ffff8880b9d2a5d8 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81683ebc R11: 0000000000000000 R12: ffff88804681ba00 R13: 0000000000000001 R14: 00000000ffffffff R15: ffff88804681c460 FS: 00007f213a420700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f213939c028 CR3: 00000000473b6000 CR4: 0000000000350ee0 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] __run_hrtimer kernel/time/hrtimer.c:1651 [inline] __hrtimer_run_queues+0x95a/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:645 RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x1c/0x60 kernel/kcov.c:200 Code: be a8 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 09 40 89 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 00 01 ff 00 74 0e 85 c9 74 35 8b 82 a4 15 00 00 85 c0 74 2b 8b RSP: 0018:ffffc900058c7d70 EFLAGS: 00000246 RAX: 0000000080000000 RBX: ffffc900058c7df0 RCX: 0000000000000000 RDX: ffff88804681ba00 RSI: ffffffff81d19ef2 RDI: 0000000000000003 RBP: 0000000000008000 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81d19ee4 R11: 0000000000000000 R12: 0000000000008000 R13: ffffc900058c7ea8 R14: 0000000000000004 R15: 0000000000000000 build_open_flags+0x72/0x6f0 fs/open.c:1045 do_sys_openat2+0x85/0x4c0 fs/open.c:1201 do_sys_open fs/open.c:1229 [inline] __do_sys_openat fs/open.c:1245 [inline] __se_sys_openat fs/open.c:1240 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1240 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: 0033:0x7f213923c004 Code: 84 00 00 00 00 00 44 89 54 24 0c e8 96 f9 ff ff 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 89 44 24 0c e8 c8 f9 ff ff 8b 44 RSP: 002b:00007f213a420090 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f213939bf60 RCX: 00007f213923c004 RDX: 0000000000000000 RSI: 00007f21392e2075 RDI: 00000000ffffff9c RBP: 00007f21392e2075 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007ffc583f189f R14: 00007f213a420300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10496 jiffies! g239521 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:28728 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5073 [inline] __schedule+0xa9a/0x4cc0 kernel/sched/core.c:6388 schedule+0xd2/0x1f0 kernel/sched/core.c:6460 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1884 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1971 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2144 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 975 Comm: kworker/u4:4 Tainted: G S 5.18.0-rc3-syzkaller-00080-gd569e86915b7 #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+0x1e6/0x230 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:490 print_other_cpu_stall kernel/rcu/tree_stall.h:595 [inline] check_cpu_stall kernel/rcu/tree_stall.h:741 [inline] rcu_pending kernel/rcu/tree.c:3923 [inline] rcu_sched_clock_irq+0x1f7c/0x2150 kernel/rcu/tree.c:2625 update_process_times+0x16d/0x200 kernel/time/timer.c:1788 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1473 __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:645 RIP: 0010:csd_lock_wait kernel/smp.c:411 [inline] RIP: 0010:smp_call_function_many_cond+0x499/0x1110 kernel/smp.c:969 Code: 01 89 ee e8 e9 cd 0b 00 85 ed 74 47 48 8b 04 24 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 fc 83 c5 03 e8 a9 cb 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 21 0a 00 00 8b 43 08 31 RSP: 0018:ffffc9000467f950 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9d3edc0 RCX: 0000000000000000 RDX: ffff88801ccd0000 RSI: ffffffff816d6407 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816d642d R11: 0000000000000000 R12: ffffed10173a7db9 R13: 0000000000000001 R14: 0000000000000001 R15: dffffc0000000000 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:1184 [inline] text_poke_bp_batch+0x22c/0x6b0 arch/x86/kernel/alternative.c:1372 text_poke_flush arch/x86/kernel/alternative.c:1542 [inline] text_poke_flush arch/x86/kernel/alternative.c:1539 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1549 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 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:764 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:756 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 ---------------- Code disassembly (best guess): 0: f6 47 22 03 testb $0x3,0x22(%rdi) 4: 0f 95 c0 setne %al 7: 45 31 ed xor %r13d,%r13d a: 44 39 f0 cmp %r14d,%eax d: 41 0f 94 c5 sete %r13b 11: 48 c7 c7 a0 5c cc 89 mov $0xffffffff89cc5ca0,%rdi 18: e8 89 0d 00 00 callq 0xda6 1d: b8 ff ff ff ff mov $0xffffffff,%eax 22: 65 0f c1 05 24 b9 98 xadd %eax,%gs:0x7698b924(%rip) # 0x7698b94e 29: 76 * 2a: 83 f8 01 cmp $0x1,%eax <-- trapping instruction 2d: 75 29 jne 0x58 2f: 9c pushfq 30: 58 pop %rax 31: f6 c4 02 test $0x2,%ah 34: 75 3d jne 0x73 36: 48 f7 04 24 00 02 00 testq $0x200,(%rsp) 3d: 00 3e: 74 01 je 0x41