rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=32a/1/0x4000000000000000 softirq=119851/119851 fqs=41 (t=10501 jiffies g=202733 q=179) rcu: rcu_preempt kthread starved for 10420 jiffies! g202733 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 28416 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x979/0xce0 kernel/sched/core.c:4527 NMI backtrace for cpu 0 CPU: 0 PID: 16852 Comm: syz-executor.4 Not tainted 5.8.0-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+0x1f0/0x31e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x199/0x2a0 kernel/rcu/tree_stall.h:318 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline] check_cpu_stall kernel/rcu/tree_stall.h:625 [inline] rcu_pending kernel/rcu/tree.c:3637 [inline] rcu_sched_clock_irq+0x1920/0x1eb0 kernel/rcu/tree.c:2519 update_process_times+0x130/0x1b0 kernel/time/timer.c:1710 tick_sched_handle kernel/time/tick-sched.c:176 [inline] tick_sched_timer+0x25e/0x410 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x42d/0x930 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0xd0/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0xd0 kernel/locking/spinlock.c:191 Code: b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 b8 14 4d 89 e8 5a cd 89 f9 48 83 3d 7a 39 22 01 00 74 2c 4c 89 f7 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 ec 02 26 f9 65 8b 05 b1 22 d7 77 RSP: 0018:ffffc90000007d00 EFLAGS: 00000282 RAX: 1ffffffff129a297 RBX: ffff8880ae825400 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000282 RBP: 00000000ffffffff R08: dffffc0000000000 R09: fffffbfff167ceba R10: fffffbfff167ceba R11: 0000000000000000 R12: ffff888212541820 R13: 0000000000000282 R14: 0000000000000282 R15: ffff888212541810 __mod_timer+0x1020/0x11f0 kernel/time/timer.c:1066 call_timer_fn+0x91/0x160 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers+0x65e/0x830 kernel/time/timer.c:1755 run_timer_softirq+0x46/0x80 kernel/time/timer.c:1768 __do_softirq+0x236/0x66c kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x91/0xe0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu+0x1e1/0x1f0 kernel/softirq.c:423 irq_exit_rcu+0x5/0x10 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0xd5/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:unwind_next_frame+0x5c3/0x1e90 arch/x86/kernel/unwind_orc.c:462 Code: 03 42 8a 04 30 84 c0 0f 85 aa 05 00 00 c6 03 01 49 c7 c7 fe bd 82 88 49 8d 6f 04 49 8d 5f 05 49 89 ec 49 c1 ec 03 43 8a 04 34 <84> c0 0f 85 47 05 00 00 48 89 d8 48 c1 e8 03 42 8a 04 30 84 c0 0f RSP: 0018:ffffc90016aa7860 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffffffff8a055fe3 RCX: dffffc0000000000 RDX: ffffffff8a055fde RSI: ffffffff81642e01 RDI: ffffffff8133d74d RBP: ffffffff8a055fe2 R08: 000000000000001c R09: ffffc90016aa79d8 R10: fffff52002d54f31 R11: 0000000000000000 R12: 1ffffffff140abfc R13: ffffc90016aa7928 R14: dffffc0000000000 R15: ffffffff8a055fde arch_stack_walk+0xb4/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xad/0x150 kernel/stacktrace.c:123 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x218/0x320 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] kzalloc+0x1d/0x40 include/linux/slab.h:666 lsm_cred_alloc security/security.c:532 [inline] security_prepare_creds+0x46/0x220 security/security.c:1631 prepare_creds+0x3dc/0x590 kernel/cred.c:285 prepare_exec_creds+0x14/0x260 kernel/cred.c:304 prepare_bprm_creds fs/exec.c:1558 [inline] bprm_execve+0xdc/0x1500 fs/exec.c:1892 do_execveat_common+0x487/0x5f0 fs/exec.c:2016 do_execve fs/exec.c:2084 [inline] __do_sys_execve fs/exec.c:2160 [inline] __se_sys_execve fs/exec.c:2155 [inline] __x64_sys_execve+0x8e/0xa0 fs/exec.c:2155 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d189 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f3092e7bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 0000000000002c80 RCX: 000000000045d189 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffe0f16120f R14: 00007f3092e7c9c0 R15: 000000000118cf4c