rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=17365, q=56) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294977129-4294966626), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.5 R running task 25368 11282 9677 0x80004000 Call Trace: sched_show_task kernel/sched/core.c:5953 [inline] sched_show_task.cold+0x2ee/0x35d kernel/sched/core.c:5928 print_other_cpu_stall kernel/rcu/tree_stall.h:430 [inline] check_cpu_stall kernel/rcu/tree_stall.h:558 [inline] rcu_pending kernel/rcu/tree.c:3097 [inline] rcu_sched_clock_irq.cold+0xb92/0xcc6 kernel/rcu/tree.c:2297 update_process_times+0x2d/0x70 kernel/time/timer.c:1726 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x90/0xe0 kernel/locking/spinlock.c:191 Code: 48 c7 c0 78 ba b3 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 39 48 83 3d 3f ae c5 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 61 d4 62 f9 65 8b 05 32 12 14 78 RSP: 0018:ffffc900167ff648 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff136774f RBX: 0000000000000286 RCX: 0000000000000007 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffffc900167ff658 R08: 1ffffffff16a51c9 R09: fffffbfff16a51ca R10: fffffbfff16a51c9 R11: ffffffff8b528e4f R12: ffffffff8ba45108 R13: ffffffff8ba45108 R14: ffff88808fc02000 R15: 0000000000000000 __debug_check_no_obj_freed lib/debugobjects.c:973 [inline] debug_check_no_obj_freed+0x20a/0x43f lib/debugobjects.c:994 free_pages_prepare mm/page_alloc.c:1168 [inline] free_pcp_prepare+0x208/0x4f0 mm/page_alloc.c:1198 free_unref_page_prepare mm/page_alloc.c:3011 [inline] free_unref_page+0x11/0x180 mm/page_alloc.c:3060 __put_single_page mm/swap.c:81 [inline] __put_page+0x105/0x3b0 mm/swap.c:115 put_page include/linux/mm.h:1029 [inline] generic_pipe_buf_release+0x1e1/0x250 fs/pipe.c:227 pipe_buf_release include/linux/pipe_fs_i.h:185 [inline] pipe_truncate lib/iov_iter.c:1029 [inline] pipe_advance lib/iov_iter.c:1061 [inline] iov_iter_advance+0x793/0xe20 lib/iov_iter.c:1067 default_file_splice_read+0x7c5/0xa20 fs/splice.c:434 do_splice_to+0x127/0x180 fs/splice.c:892 splice_direct_to_actor+0x320/0xa30 fs/splice.c:971 do_splice_direct+0x1da/0x2a0 fs/splice.c:1080 do_sendfile+0x597/0xd00 fs/read_write.c:1464 __do_sys_sendfile64 fs/read_write.c:1525 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b399 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:00007fa5aad87c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fa5aad886d4 RCX: 000000000045b399 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffa R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008ca R14: 00000000004ca24d R15: 000000000075bf2c rcu: rcu_preempt kthread starved for 10549 jiffies! g17365 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29008 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1670 [inline] rcu_gp_kthread+0xa10/0x1b40 kernel/rcu/tree.c:1837 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352