rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=f2a/1/0x4000000000000002 softirq=13559/13560 fqs=3 (t=10501 jiffies g=6813 q=119) rcu: rcu_preempt kthread starved for 10496 jiffies! g6813 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 28536 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 0 CPU: 0 PID: 8453 Comm: syz-executor.0 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:__memcg_kmem_uncharge+0x8/0x1a0 mm/memcontrol.c:2908 Code: 07 00 74 12 48 81 c3 08 02 00 00 48 89 df 4c 89 f6 e8 8c 85 ff ff 5b 41 5e 5d c3 0f 1f 80 00 00 00 00 55 48 89 e5 41 57 41 56 <41> 55 41 54 53 50 89 f3 49 89 fc 48 b8 00 00 00 00 00 fc ff df 4c RSP: 0018:ffffc90001ec73f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81489244 RBX: ffffea000231bdc0 RCX: ffff8880a24f0140 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea000231bdc0 RBP: ffffc90001ec7408 R08: 000000000003a728 R09: fffffbfff124248a R10: fffffbfff124248a R11: 0000000000000000 R12: ffff888099895aa0 R13: dffffc0000000000 R14: 1ffff11013312b54 R15: ffff88808b50b4b8 memcg_kmem_uncharge include/linux/memcontrol.h:1402 [inline] free_thread_stack+0x12e/0x590 kernel/fork.c:284 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+0x44b/0x530 arch/x86/kernel/unwind_frame.c:248 Code: 89 e7 e8 f8 ee 7d 00 41 83 3c 24 00 0f 85 47 ff ff ff 45 31 ed 48 bb 00 00 00 00 00 fc ff df 4c 89 f0 48 c1 e8 03 80 3c 18 00 <74> 08 4c 89 f7 e8 eb ee 7d 00 65 48 8b 04 25 c0 1d 02 00 49 39 06 RSP: 0018:ffffc90001ec7668 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff920003d8f0f RBX: dffffc0000000000 RCX: 1ffff920003d8f0a RDX: ffffc90001ec78f0 RSI: 1ffff920003d8f0c RDI: ffffc90001ec7850 RBP: ffffc90001ec7710 R08: dffffc0000000000 R09: ffffc90001ec7850 R10: fffff520003d8f16 R11: 0000000000000000 R12: ffffc90001ec7850 R13: ffffc90001ec78e8 R14: ffffc90001ec7878 R15: 1ffff920003d8f12 unwind_next_frame+0x3f1/0x7a0 arch/x86/kernel/unwind_frame.c:311 __unwind_start+0x36a/0x440 arch/x86/kernel/unwind_frame.c:410 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0x78/0xe0 arch/x86/kernel/stacktrace.c:24 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_trace+0x1fa/0x2f0 mm/slab.c:3549 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:670 [inline] freezer_css_alloc+0x47/0x70 kernel/cgroup/legacy_freezer.c:90 css_create kernel/cgroup/cgroup.c:5097 [inline] cgroup_apply_control_enable+0x664/0x1240 kernel/cgroup/cgroup.c:3064 cgroup_mkdir+0xeb8/0x1280 kernel/cgroup/cgroup.c:5327 kernfs_iop_mkdir+0x133/0x270 fs/kernfs/dir.c:1127 vfs_mkdir+0x43f/0x610 fs/namei.c:3819 do_mkdirat+0x1d7/0x320 fs/namei.c:3842 __do_sys_mkdir fs/namei.c:3858 [inline] __se_sys_mkdir fs/namei.c:3856 [inline] __x64_sys_mkdir+0x60/0x70 fs/namei.c:3856 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a367 Code: 1f 40 00 b8 5a 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 7d c2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 5d c2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe92693808 EFLAGS: 00000202 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000045a367 RDX: 00007ffe92693863 RSI: 00000000000001ff RDI: 00007ffe92693850 RBP: 00000000000000f8 R08: 0000000000000000 R09: 0000000000000013 R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000416a50 R13: 00007ffe92693c78 R14: 0000000000000000 R15: 00007ffe92693850