rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=49613, q=79) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294994492-4294983989), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.1 R running task 26528 21553 8541 0x00004000 Call Trace: sched_show_task kernel/sched/core.c:5285 [inline] sched_show_task.cold+0x291/0x2fc kernel/sched/core.c:5260 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline] check_cpu_stall kernel/rcu/tree_stall.h:536 [inline] rcu_pending kernel/rcu/tree.c:2625 [inline] rcu_sched_clock_irq.cold+0xaaf/0xbfd kernel/rcu/tree.c:2161 update_process_times+0x32/0x80 kernel/time/timer.c:1639 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1388 [inline] __hrtimer_run_queues+0x33b/0xdd0 kernel/time/hrtimer.c:1450 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1508 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] smp_apic_timer_interrupt+0x111/0x550 arch/x86/kernel/apic/apic.c:1066 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 RIP: 0010:__kernel_text_address+0x1/0x40 kernel/extable.c:94 Code: 89 e7 e8 92 98 30 00 0f b6 c0 eb e0 48 c7 c7 c4 f3 a0 89 e8 31 57 5e 00 e9 69 ff ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 55 <48> 89 e5 53 48 89 fb e8 03 ff ff ff 85 c0 75 18 48 81 fb 00 a0 ad RSP: 0018:ffff888054d6f4e0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffff888054d6f510 RCX: 0000000000000000 RDX: 1ffff1100a9adeab RSI: 1ffff1100a9ade00 RDI: ffffffff81c02aae RBP: ffff888054d6f500 R08: 0000000000000001 R09: ffff888054d6f568 R10: ffff888054d6f538 R11: ffff888054d6f548 R12: ffff888054d6f558 R13: 0000000000000000 R14: ffff88805ae82300 R15: ffff8880aa4008c0 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xac/0xe0 kernel/stacktrace.c:123 save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:497 slab_post_alloc_hook mm/slab.h:511 [inline] slab_alloc mm/slab.c:3311 [inline] __do_kmalloc mm/slab.c:3643 [inline] __kmalloc+0x145/0x740 mm/slab.c:3654 kmalloc_array include/linux/slab.h:671 [inline] kcalloc include/linux/slab.h:682 [inline] iter_file_splice_write+0x16e/0xbd0 fs/splice.c:690 do_splice_from fs/splice.c:848 [inline] direct_splice_actor+0x123/0x190 fs/splice.c:1020 splice_direct_to_actor+0x366/0x970 fs/splice.c:975 do_splice_direct+0x1da/0x2a0 fs/splice.c:1063 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+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: fd 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f6497540c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000004592c9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00008000fffffffe R11: 0000000000000246 R12: 00007f64975416d4 R13: 00000000004c689d R14: 00000000004db828 R15: 00000000ffffffff rcu: rcu_preempt kthread starved for 10557 jiffies! g49613 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29224 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x7c5/0x1560 kernel/sched/core.c:3444 schedule+0xa8/0x260 kernel/sched/core.c:3508 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1807 rcu_gp_fqs_loop kernel/rcu/tree.c:1589 [inline] rcu_gp_kthread+0x9b2/0x18b0 kernel/rcu/tree.c:1746 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352