rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=02a/1/0x4000000000000002 softirq=14789/14789 fqs=143 (t=10500 jiffies g=7405 q=115) rcu: rcu_preempt kthread starved for 10206 jiffies! g7405 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 28984 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 8763 Comm: syz-executor.2 Not tainted 5.5.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fb/0x318 lib/dump_stack.c:118 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:mod_memcg_page_state+0x6/0x190 include/linux/memcontrol.h:652 Code: 60 00 eb 0c e8 eb 27 2e 00 eb 05 e8 e4 27 2e 00 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 44 00 00 55 48 89 e5 41 57 <41> 56 41 54 53 41 89 f6 48 89 fb e8 ba 27 2e 00 48 83 c3 38 48 89 RSP: 0018:ffffc90001dd75a0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff11011bd3cd1 RBX: ffff88808de9e688 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea000275a340 RBP: ffffc90001dd75a8 R08: dffffc0000000000 R09: fffffbfff124248a R10: fffffbfff124248a R11: 0000000000000000 R12: ffff88808de9e720 R13: dffffc0000000000 R14: 1ffff11011bd3ce4 R15: ffff8880a843d8b8 free_thread_stack+0x168/0x590 kernel/fork.c:280 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338 retint_kernel+0x1b/0x2b RIP: 0010:update_stack_state+0x4ad/0x530 include/linux/compiler.h:199 Code: ee 7d 00 48 8b 5d c8 4c 8b 75 c0 eb 1d 4c 89 e8 48 c1 e8 03 80 3c 18 00 4c 8b 75 c0 74 08 4c 89 ef e8 97 ee 7d 00 49 8b 5d 00 <49> 83 c4 48 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 RSP: 0018:ffffc90001dd7800 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff920003bafe3 RBX: ffffffff810079c7 RCX: 1ffff920003baf2c RDX: ffffc90001dd7f20 RSI: 1ffff920003baf2e RDI: ffffc90001dd7960 RBP: ffffc90001dd78a8 R08: ffffffff8165c2fd R09: ffffc90001dd7960 R10: fffff520003baf38 R11: 0000000000000000 R12: ffffc90001dd7960 R13: ffffc90001dd7f18 R14: ffffc90001dd79a0 R15: 1ffff920003baf34 unwind_next_frame+0x3f1/0x7a0 arch/x86/kernel/unwind_frame.c:311 arch_stack_walk+0xb4/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xb6/0x150 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:513 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:521 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x1f5/0x2e0 mm/slab.c:3484 kmem_cache_zalloc include/linux/slab.h:660 [inline] __alloc_file+0x2c/0x390 fs/file_table.c:101 alloc_empty_file+0xac/0x1b0 fs/file_table.c:151 alloc_file+0x60/0x4c0 fs/file_table.c:193 alloc_file_pseudo+0x1d4/0x260 fs/file_table.c:232 sock_alloc_file+0xbb/0x260 net/socket.c:398 sock_map_fd net/socket.c:422 [inline] __sys_socket+0x14b/0x2e0 net/socket.c:1517 __do_sys_socket net/socket.c:1522 [inline] __se_sys_socket net/socket.c:1520 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1520 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45da97 Code: 00 00 00 49 89 ca b8 36 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4a 8b fb ff c3 66 0f 1f 84 00 00 00 00 00 b8 29 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 2d 8b fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe9a92edb8 EFLAGS: 00000202 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045da97 RDX: 0000000000000000 RSI: 0000000000080002 RDI: 0000000000000001 RBP: 00000000004c0426 R08: 00007ffe9a92ee43 R09: 000000000000000f R10: 0000000000000004 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000000006 R15: 00007ffe9a92f180