rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=241837, q=44) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295130505-4295120003), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.2 R running task 26880 5649 9735 0x00004000 Call Trace: sched_show_task kernel/sched/core.c:5952 [inline] sched_show_task.cold+0x2e2/0x343 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+0xb35/0xc55 kernel/rcu/tree.c:2276 update_process_times+0x25/0x60 kernel/time/timer.c:1726 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:171 tick_sched_timer+0x4e/0x140 kernel/time/tick-sched.c:1314 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x32c/0xdd0 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline] smp_apic_timer_interrupt+0x15b/0x600 arch/x86/kernel/apic/apic.c:1144 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:stack_trace_consume_entry+0xab/0x160 kernel/stacktrace.c:93 Code: c0 03 38 d0 7c 08 84 d2 0f 85 90 00 00 00 8b 43 0c 85 c0 75 53 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 <0f> 85 92 00 00 00 8d 45 01 89 43 10 48 8b 03 48 8d 2c e8 48 b8 00 RSP: 0018:ffffc90017d3f568 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffffc90017d3f638 RCX: 0000000000000000 RDX: 1ffff92002fa7ec7 RSI: ffffffff81ae5cd1 RDI: ffffc90017d3f644 RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000001 R10: 00000000000279bd R11: 000000000006e027 R12: ffffc90017d3f638 R13: 0000000000000000 R14: ffff8880449aa440 R15: ffff88809dd226ff arch_stack_walk+0x67/0xd0 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488 __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+0x1a8/0x270 fs/splice.c:1080 do_sendfile+0x549/0xc40 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+0x149/0x210 fs/read_write.c:1567 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c679 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:00007f97ced29c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f97ced2a6d4 RCX: 000000000045c679 RDX: 00000000200001c0 RSI: 0000000000000005 RDI: 0000000000000005 RBP: 000000000076c040 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d1 R14: 00000000004cb581 R15: 000000000076c04c rcu: rcu_preempt kthread starved for 10502 jiffies! g241837 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29384 10 2 0x80004000 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4154 schedule_timeout+0x474/0xba0 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1658 [inline] rcu_gp_kthread+0x9d9/0x17d0 kernel/rcu/tree.c:1818 kthread+0x357/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 sched: RT throttling activated