rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=11861, q=84) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294968945-4294958442), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.2 R running task 25832 9750 9183 0x00004000 Call Trace: sched_show_task kernel/sched/core.c:5753 [inline] sched_show_task.cold+0x2ed/0x34e kernel/sched/core.c:5728 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:2736 [inline] rcu_sched_clock_irq.cold+0xac8/0xc13 kernel/rcu/tree.c:2183 update_process_times+0x32/0x80 kernel/time/timer.c:1639 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1068 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1093 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:unwind_next_frame.part.0+0x35c/0xa20 arch/x86/kernel/unwind_frame.c:363 Code: 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 14 02 00 00 c7 03 00 00 00 00 31 c0 48 ba 00 00 00 00 00 fc ff df 49 c7 04 14 00 00 00 00 <48> 8b 4d d0 65 48 33 0c 25 28 00 00 00 0f 85 43 03 00 00 48 81 c4 RSP: 0018:ffff888057d17438 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffff888057d17510 RCX: 1ffff1100afa2eaa RDX: dffffc0000000000 RSI: 1ffff1100afa2e00 RDI: ffff888057d17558 RBP: ffff888057d174e8 R08: 0000000000000001 R09: ffff888057d17568 R10: ffff888057d17538 R11: ffff888057d17548 R12: 1ffff1100afa2e8c R13: 0000000000000000 R14: ffff888057d17f10 R15: ffff888057d17f48 unwind_next_frame+0x3b/0x50 arch/x86/kernel/unwind_frame.c:265 arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 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:520 [inline] slab_alloc mm/slab.c:3320 [inline] __do_kmalloc mm/slab.c:3654 [inline] __kmalloc+0x14c/0x770 mm/slab.c:3665 kmalloc_array include/linux/slab.h:675 [inline] kcalloc include/linux/slab.h:686 [inline] iter_file_splice_write+0x16e/0xbe0 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/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4597c9 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:00007fea45b63c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000004597c9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00008000fffffffe R11: 0000000000000246 R12: 00007fea45b646d4 R13: 00000000004c6def R14: 00000000004dc128 R15: 00000000ffffffff rcu: rcu_preempt kthread starved for 10561 jiffies! g11861 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29112 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3252 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3878 schedule+0xa8/0x270 kernel/sched/core.c:3942 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1807 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline] rcu_gp_kthread+0x9b2/0x18c0 kernel/rcu/tree.c:1768 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:353