rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=5d6/1/0x4000000000000000 softirq=14136/14137 fqs=1 (detected by 0, t=10502 jiffies, g=22121, q=49) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10353 Comm: syz-executor.1 Not tainted 5.9.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:advance_sched+0x2/0x990 net/sched/sch_taprio.c:691 Code: e8 93 03 1a fb e9 8f fd ff ff e8 89 03 1a fb e9 a9 fd ff ff 4c 89 ff e8 7c 03 1a fb e9 86 fc ff ff 0f 1f 80 00 00 00 00 41 57 <41> 56 41 55 41 54 55 53 48 89 fb 48 83 ec 38 e8 ca 2b d9 fa 48 8d RSP: 0000:ffffc90000da8de0 EFLAGS: 00000046 RAX: ffffffff869d12b0 RBX: ffff8880a7bce580 RCX: ffffffff816652ed RDX: ffff8880a7bce580 RSI: ffffffff816652fa RDI: ffff8880a2121340 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8b597d0f R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ae527740 R13: ffff8880ae527840 R14: ffff8880a2121340 R15: dffffc0000000000 FS: 0000000001e3b940(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000580 CR3: 000000008b218000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x6a9/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x147/0x5f0 arch/x86/kernel/apic/apic.c:1097 asm_call_irq_on_stack+0xf/0x20 __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline] run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline] sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:66 Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 RSP: 0000:ffffc90006587998 EFLAGS: 00010206 RAX: 1ffff11009780000 RBX: ffffed1009780000 RCX: 0000000000013540 RDX: 0000000000040000 RSI: 0000000000000000 RDI: ffffed100976cac0 RBP: 0000000000200000 R08: 0000000000000001 R09: ffffed1009740000 R10: fffff9400025d006 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000009 R14: 00000000003d20ca R15: ffff88812fffb700 kasan_poison_shadow mm/kasan/common.c:130 [inline] kasan_unpoison_shadow mm/kasan/common.c:144 [inline] kasan_alloc_pages+0x59/0x70 mm/kasan/common.c:194 post_alloc_hook mm/page_alloc.c:2217 [inline] prep_new_page+0xfa/0x1f0 mm/page_alloc.c:2225 get_page_from_freelist+0x2bf6/0x3be0 mm/page_alloc.c:3844 __alloc_pages_nodemask+0x2cf/0x790 mm/page_alloc.c:4895 __alloc_pages include/linux/gfp.h:509 [inline] __alloc_pages_node include/linux/gfp.h:522 [inline] alloc_pages_vma+0x56e/0x730 mm/mempolicy.c:2219 do_huge_pmd_anonymous_page+0x3e9/0x2200 mm/huge_memory.c:748 create_huge_pmd mm/memory.c:4282 [inline] __handle_mm_fault mm/memory.c:4506 [inline] handle_mm_fault+0x369d/0x4590 mm/memory.c:4633 do_user_addr_fault+0x598/0xbf0 arch/x86/mm/fault.c:1372 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0xa8/0x190 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:538 RIP: 0033:0x4450f7 Code: 0b 0f b6 0e 88 0f 48 ff c6 48 ff c7 f6 c2 02 74 12 0f b7 0e 66 89 0f 48 83 c6 02 48 83 c7 02 0f 1f 40 00 f6 c2 04 74 0c 8b 0e <89> 0f 48 83 c6 04 48 83 c7 04 f6 c2 08 74 0e 48 8b 0e 48 89 0f 48 RSP: 002b:00007fffa3448208 EFLAGS: 00010202 RAX: 0000000020000580 RBX: 0000000000000000 RCX: 000000007665642f RDX: 000000000000000c RSI: 0000000001190020 RDI: 0000000020000580 RBP: 0000000001190000 R08: 0000000000000000 R09: 0000000000000004 R10: 0000000000000075 R11: 0000000000000246 R12: 0000000001190008 R13: 00007fffa3448400 R14: fffffffffffffffe R15: 00007fffa3448410 rcu: rcu_preempt kthread starved for 10500 jiffies! g22121 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:29344 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0xec9/0x2280 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879 rcu_gp_fqs_loop kernel/rcu/tree.c:1890 [inline] rcu_gp_kthread+0xb2c/0x1ca0 kernel/rcu/tree.c:2060 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294