rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3791/1:b..l (detected by 1, t=10503 jiffies, g=10997, q=64) task:syz-executor.3 state:R running task stack:20888 pid: 3791 ppid: 3781 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:643 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x7c/0x80 kernel/kcov.c:286 Code: 8d 42 28 4c 39 d0 77 22 89 f8 89 f6 48 c7 44 0a 08 05 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 49 ff c1 4c 89 09 0f 1f 00 4c 8b 04 24 65 48 8b 0d 14 0f 82 7e 65 8b 05 15 0f 82 RSP: 0018:ffffc90004d975f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88801e230000 RDX: ffff88801e230000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff818cff69 R09: fffffbfff1f7f019 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 0000000000000000 R14: 00007f1a055876c7 R15: 0000000000000144 rcu_read_unlock include/linux/rcupdate.h:768 [inline] is_bpf_text_address+0x1c9/0x260 kernel/bpf/core.c:723 kernel_text_address kernel/extable.c:151 [inline] __kernel_text_address+0x94/0x100 kernel/extable.c:105 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf3/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 jbd2_free_handle include/linux/jbd2.h:1602 [inline] jbd2_journal_stop+0x8d9/0xd70 fs/jbd2/transaction.c:1964 __ext4_journal_stop+0xf8/0x190 fs/ext4/ext4_jbd2.c:127 ext4_rmdir+0x8fb/0xa80 fs/ext4/namei.c:3228 vfs_rmdir+0x305/0x460 fs/namei.c:4149 do_rmdir+0x368/0x670 fs/namei.c:4210 __do_sys_unlinkat fs/namei.c:4390 [inline] __se_sys_unlinkat fs/namei.c:4384 [inline] __x64_sys_unlinkat+0xdc/0xf0 fs/namei.c:4384 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f1a055876c7 RSP: 002b:00007ffdb8ce2aa8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f1a055876c7 RDX: 0000000000000200 RSI: 00007ffdb8ce3c20 RDI: 00000000ffffff9c RBP: 00007f1a055d3336 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffdb8ce3c20 R13: 00007f1a055d3336 R14: 0000000000017c8b R15: 0000000000000005 rcu: rcu_preempt kthread starved for 10548 jiffies! g10997 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: task:rcu_preempt state:R running task stack:27000 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:schedule+0x108/0x1f0 kernel/sched/core.c:6461 Code: 0e eb a3 f7 49 8b 07 4c 39 f8 74 0d 4c 89 f7 be 01 00 00 00 e8 a9 c2 c6 f9 4c 89 eb 48 c1 eb 03 eb 0a 49 f7 45 00 08 00 00 00 <74> 39 bf 01 00 00 00 e8 7c 20 31 f7 31 ff e8 35 b9 ff ff bf 01 00 RSP: 0018:ffffc90000d47b70 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 1ffff11027fc4770 RCX: ffffffff8a264012 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88813fe23b80 RBP: ffffc90000d47c90 R08: dffffc0000000000 R09: ffffed1027fc4771 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff88813fe23b80 R14: 0000000000000000 R15: 00000000ffffb06a schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 4551 Comm: syz-executor.4 Not tainted 5.15.159-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x3e/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0033:0x7f57f1352ee7 Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 RSP: 002b:00007f57ef8a5178 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f57f1482058 RCX: 00007f57f1352ee9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f57f1482058 RBP: 00007f57f1482050 R08: 00007f57ef8a56c0 R09: 00007f57ef8a56c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f57f148205c R13: 000000000000006e R14: 00007fffeec37120 R15: 00007fffeec37208 sched: RT throttling activated