rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=142/1/0x4000000000000002 softirq=132681/132681 fqs=24 rcu: (t=10501 jiffies g=187009 q=297) rcu: rcu_preempt kthread starved for 10454 jiffies! g187009 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29152 10 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x4d1/0xf20 kernel/time/timer.c:1806 rcu_gp_kthread+0xcee/0x2060 kernel/rcu/tree.c:2202 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 NMI backtrace for cpu 0 CPU: 0 PID: 20725 Comm: syz-executor.0 Not tainted 4.19.107-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+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x170/0x1bb kernel/rcu/tree.c:1340 print_cpu_stall kernel/rcu/tree.c:1478 [inline] check_cpu_stall kernel/rcu/tree.c:1550 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0x634/0xddc kernel/rcu/tree.c:2682 update_process_times+0x2a/0x70 kernel/time/timer.c:1638 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168 tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x2fc/0xd50 kernel/time/hrtimer.c:1463 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1521 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:lock_is_held_type+0x17a/0x210 kernel/locking/lockdep.c:3943 Code: 00 00 00 00 fc ff df c7 85 7c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 75 63 48 83 3d 25 75 63 07 00 74 2c 48 89 df 57 9d <0f> 1f 44 00 00 48 83 c4 08 44 89 e0 5b 5d 41 5c c3 48 83 c4 08 41 RSP: 0018:ffff88804601f2b8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff1164ad1 RBX: 0000000000000282 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff88b92960 RDI: 0000000000000282 RBP: ffff88804a924580 R08: ffff88804a924580 R09: ffffed1015cc4733 R10: ffffed1015cc4732 R11: ffff8880ae623993 R12: 0000000000000000 R13: 0000000000000000 R14: 000000000118f0a8 R15: ffffffff81e5c078 lock_is_held include/linux/lockdep.h:344 [inline] rcu_read_lock_sched_held+0x10a/0x130 kernel/rcu/update.c:118 trace_ext4_mark_inode_dirty include/trace/events/ext4.h:248 [inline] ext4_mark_inode_dirty+0x767/0x890 fs/ext4/inode.c:6090 ext4_dirty_inode+0x88/0xb0 fs/ext4/inode.c:6130 __mark_inode_dirty+0x8d8/0x1240 fs/fs-writeback.c:2176 mark_inode_dirty include/linux/fs.h:2082 [inline] __generic_write_end+0x28d/0x330 fs/buffer.c:2118 ext4_da_write_end+0x3d0/0xaa0 fs/ext4/inode.c:3193 generic_perform_write+0x2ae/0x4d0 mm/filemap.c:3173 __generic_file_write_iter+0x24c/0x610 mm/filemap.c:3287 ext4_file_write_iter+0x2fe/0xf90 fs/ext4/file.c:272 call_write_iter include/linux/fs.h:1820 [inline] do_iter_readv_writev+0x50c/0x790 fs/read_write.c:681 rcu: INFO: rcu_sched detected stalls on CPUs/tasks: rcu: 0-...!: (10548 ticks this GP) idle=142/1/0x4000000000000002 softirq=132627/132681 fqs=2 do_iter_write fs/read_write.c:960 [inline] do_iter_write+0x185/0x5e0 fs/read_write.c:941 rcu: (detected by 1, t=10502 jiffies, g=17209, q=1) rcu: rcu_sched kthread starved for 10498 jiffies! g17209 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_sched R running task 29616 11 2 0x80000000 vfs_iter_write+0x70/0xa0 fs/read_write.c:973 Call Trace: iter_file_splice_write+0x60c/0xb30 fs/splice.c:750 schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x4d1/0xf20 kernel/time/timer.c:1806 do_splice_from fs/splice.c:852 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1025 splice_direct_to_actor+0x33f/0x8d0 fs/splice.c:980 rcu_gp_kthread+0xcee/0x2060 kernel/rcu/tree.c:2202 do_splice_direct+0x1a8/0x270 fs/splice.c:1068 do_sendfile+0x549/0xc10 fs/read_write.c:1447 kthread+0x34a/0x420 kernel/kthread.c:246 __do_sys_sendfile64 fs/read_write.c:1502 [inline] __se_sys_sendfile64 fs/read_write.c:1494 [inline] __x64_sys_sendfile64+0x149/0x210 fs/read_write.c:1494 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2b4df7ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f2b4df7f6d4 RCX: 000000000045c479 RDX: 00000000200001c0 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d1 R14: 00000000004cb364 R15: 000000000076c06c