rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=347/1/0x4000000000000000 softirq=56305/56306 fqs=515 (t=10500 jiffies g=73837 q=302) rcu: rcu_preempt kthread starved for 9348 jiffies! g73837 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:26816 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 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:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562 NMI backtrace for cpu 0 CPU: 0 PID: 14088 Comm: syz.1.2336 Not tainted 5.15.165-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 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_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x320/0x600 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0x8d9/0x1150 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+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__find_get_block+0x2c8/0x1350 fs/buffer.c:1308 Code: ff 49 39 de 0f 84 a6 03 00 00 e8 d3 de 9a ff 49 83 fd f1 0f 85 fa fe ff ff e8 c4 de 9a ff 45 31 e4 e8 4c 5f a1 ff fb 4d 85 e4 <74> 6b e8 b1 de 9a ff 4c 89 e7 e8 49 d8 ff ff 48 c7 44 24 60 0e 36 RSP: 0018:ffffc90002f975a0 EFLAGS: 00000246 RAX: a7c1d5a06e6cfc00 RBX: 0000000000000031 RCX: ffffffff81631a88 RDX: dffffc0000000000 RSI: ffffffff8a8b2a20 RDI: ffffffff8ad8f7c0 RBP: ffffc90002f976e8 R08: dffffc0000000000 R09: fffffbfff1f8e267 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: fffffffffffffff1 R14: 0000000000411086 R15: 00000000000365b0 __getblk_gfp+0x2d/0xaf0 fs/buffer.c:1332 __bread_gfp+0x2a/0x390 fs/buffer.c:1381 sb_bread include/linux/buffer_head.h:337 [inline] bfs_find_entry+0x1c3/0x3f0 fs/bfs/dir.c:337 bfs_lookup+0x147/0x270 fs/bfs/dir.c:137 lookup_open fs/namei.c:3440 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x111d/0x2f20 fs/namei.c:3739 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x4f0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_open fs/open.c:1277 [inline] __se_sys_open fs/open.c:1273 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1273 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: 0033:0x7efedd133e79 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007efedb56e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007efedd2d0130 RCX: 00007efedd133e79 RDX: 0000000000000000 RSI: 000000000014927e RDI: 0000000020000180 RBP: 00007efedd1a193e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007efedd2d0130 R15: 00007ffd834c05c8