rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10498 ticks this GP) idle=27e/1/0x4000000000000002 softirq=84835/84835 fqs=17 (t=10500 jiffies g=147293 q=439) rcu: rcu_preempt kthread starved for 10461 jiffies! g147293 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 28848 10 2 0x80004000 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_timeout+0x35c/0x850 kernel/time/timer.c:1898 rcu_gp_fqs_loop kernel/rcu/tree.c:1674 [inline] rcu_gp_kthread+0x9bf/0x1960 kernel/rcu/tree.c:1836 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 6915 Comm: syz-executor.3 Not tainted 5.7.0-rc3-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x19b/0x1e5 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:475 [inline] check_cpu_stall kernel/rcu/tree_stall.h:549 [inline] rcu_pending kernel/rcu/tree.c:3225 [inline] rcu_sched_clock_irq.cold+0x55d/0xcfa kernel/rcu/tree.c:2296 update_process_times+0x25/0x60 kernel/time/timer.c:1727 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x4e/0x140 kernel/time/tick-sched.c:1320 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x5ca/0xed0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 [inline] smp_apic_timer_interrupt+0x15b/0x600 arch/x86/kernel/apic/apic.c:1138 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:lock_is_held_type+0x270/0x350 kernel/locking/lockdep.c:4976 Code: 03 80 3c 10 00 0f 85 c2 00 00 00 48 83 3d d7 14 3c 08 00 74 32 48 8b 7c 24 10 57 9d 0f 1f 44 00 00 48 83 c4 18 44 89 e0 5b 5d <41> 5c 41 5d 41 5e 41 5f c3 45 31 e4 e9 6e ff ff ff 41 bc 01 00 00 RSP: 0000:ffffc900035a75d0 EFLAGS: 00000296 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: ffffc900035a76d0 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffff888022925900 RDI: 0000000000000286 RBP: 000000000000003f R08: ffff888095bac600 R09: ffffed1015ce7104 R10: ffff8880ae73881b R11: ffffed1015ce7103 R12: 0000000000000000 R13: ffff888095bacef0 R14: ffff888095bacec0 R15: ffff888022925900 lock_is_held include/linux/lockdep.h:406 [inline] xa_entry include/linux/xarray.h:1180 [inline] xas_descend+0x29d/0x360 lib/xarray.c:204 xas_load+0xe5/0x140 lib/xarray.c:240 find_get_entry+0x138/0x730 mm/filemap.c:1511 pagecache_get_page+0x47/0xa10 mm/filemap.c:1609 find_get_page include/linux/pagemap.h:258 [inline] generic_file_buffered_read mm/filemap.c:2032 [inline] generic_file_read_iter+0x6b4/0x2b10 mm/filemap.c:2309 ext4_file_read_iter fs/ext4/file.c:131 [inline] ext4_file_read_iter+0x1d1/0x600 fs/ext4/file.c:114 call_read_iter include/linux/fs.h:1901 [inline] generic_file_splice_read+0x479/0x780 fs/splice.c:313 do_splice_to+0x114/0x160 fs/splice.c:892 splice_direct_to_actor+0x307/0x980 fs/splice.c:971 do_splice_direct+0x1b4/0x280 fs/splice.c:1080 do_sendfile+0x555/0xc50 fs/read_write.c:1521 __do_sys_sendfile64 fs/read_write.c:1576 [inline] __se_sys_sendfile64 fs/read_write.c:1568 [inline] __x64_sys_sendfile64+0x149/0x210 fs/read_write.c:1568 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd993162c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fc0c0 RCX: 000000000045c829 RDX: 00000000200001c0 RSI: 0000000000000005 RDI: 0000000000000005 RBP: 000000000078c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d6 R14: 00000000004cb7a1 R15: 00007fd9931636d4