rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=158873, q=57) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295056637-4295046134), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.0 R running task 27304 2829 7090 0x00004000 Call Trace: sched_show_task kernel/sched/core.c:5961 [inline] sched_show_task.cold+0x2e2/0x343 kernel/sched/core.c:5936 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:3225 [inline] rcu_sched_clock_irq.cold+0xb9b/0xd00 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:orc_find arch/x86/kernel/unwind_orc.c:163 [inline] RIP: 0010:unwind_next_frame+0x243/0x19d0 arch/x86/kernel/unwind_orc.c:407 Code: 53 ff 39 d0 0f 83 30 01 00 00 48 ba 00 00 00 00 00 fc ff df 89 c6 48 8d 3c b5 dc 45 73 8b 49 89 f8 49 c1 e8 03 45 0f b6 04 10 <48> 89 fa 83 e2 07 83 c2 03 44 38 c2 7c 32 45 84 c0 74 2d 48 89 74 RSP: 0018:ffffc9001759f4b0 EFLAGS: 00000a07 ORIG_RAX: ffffffffffffff13 RAX: 0000000000006258 RBX: 1ffff92002eb3e9e RCX: ffffffff8162584b RDX: dffffc0000000000 RSI: 0000000000006258 RDI: ffffffff8b74cf3c RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000000000000a51b R11: 000000000007001f R12: ffffc9001759f5d0 R13: ffffc9001759f5bd R14: ffffc9001759f5d8 R15: ffffc9001759f588 arch_stack_walk+0x74/0xd0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x161/0x7a0 mm/slab.c:3665 kmalloc_array include/linux/slab.h:597 [inline] kcalloc include/linux/slab.h:608 [inline] iter_file_splice_write+0x168/0xb00 fs/splice.c:702 do_splice_from fs/splice.c:863 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1037 splice_direct_to_actor+0x38c/0x980 fs/splice.c:992 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:00007f13b02a3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fc040 RCX: 000000000045c829 RDX: 00000000200000c0 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080ffffff10 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d6 R14: 00000000004cb7a1 R15: 00007f13b02a46d4 rcu: rcu_preempt kthread starved for 10559 jiffies! g158873 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:4163 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