rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=127057, q=66) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295027944-4295017442), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.4 R running task 25656 28709 10464 0x00004000 Call Trace: sched_show_task kernel/sched/core.c:5952 [inline] sched_show_task.cold+0x2ee/0x35d kernel/sched/core.c:5927 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:3030 [inline] rcu_sched_clock_irq.cold+0xb23/0xc37 kernel/rcu/tree.c:2276 update_process_times+0x2d/0x70 kernel/time/timer.c:1726 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:171 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1314 __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:1119 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1144 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:155 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x20/0x50 kernel/kcov.c:187 Code: 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 65 48 8b 04 25 c0 1e 02 00 65 8b 15 e4 8b 8c 7e 81 e2 00 01 1f 00 48 8b 75 08 75 2b <8b> 90 80 13 00 00 83 fa 02 75 20 48 8b 88 88 13 00 00 8b 80 84 13 RSP: 0018:ffffc90004147ab8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff8880a12d05c0 RBX: 0000000000010000 RCX: 0000000000010000 RDX: 0000000000000000 RSI: ffffffff81be9e92 RDI: 0000000000000000 RBP: ffffc90004147ab8 R08: ffff8880a12d05c0 R09: fffffbfff16a337f R10: fffffbfff16a337e R11: ffffffff8b519bf7 R12: ffff88809fbc6540 R13: ffffc90004147be8 R14: 0000000000000000 R15: 0000000000000000 rw_verify_area+0x22/0x360 fs/read_write.c:371 do_splice_to+0x88/0x180 fs/splice.c:880 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:1520 __do_sys_sendfile64 fs/read_write.c:1575 [inline] __se_sys_sendfile64 fs/read_write.c:1567 [inline] __x64_sys_sendfile64+0x15a/0x220 fs/read_write.c:1567 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c449 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:00007f3aa8975c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f3aa89766d4 RCX: 000000000045c449 RDX: 00000000200001c0 RSI: 0000000000000005 RDI: 0000000000000005 RBP: 000000000076c100 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d0 R14: 00000000004cb335 R15: 000000000076c10c rcu: rcu_preempt kthread starved for 10502 jiffies! g127057 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29264 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4080 schedule+0xdc/0x2b0 kernel/sched/core.c:4154 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1658 [inline] rcu_gp_kthread+0xa10/0x1940 kernel/rcu/tree.c:1818 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352