rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=53857, q=16) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295007909-4294997406), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.2 R running task 25784 7516 9932 0x00004000 Call Trace: sched_show_task kernel/sched/core.c:5954 [inline] sched_show_task.cold+0x2ee/0x35d kernel/sched/core.c:5929 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline] check_cpu_stall kernel/rcu/tree_stall.h:538 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq.cold+0xaf4/0xc0d kernel/rcu/tree.c:2271 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:1110 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:747 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:769 [inline] RIP: 0010:lock_acquire+0x81/0x410 kernel/locking/lockdep.c:4479 Code: c9 0f 85 03 03 00 00 8b b2 94 08 00 00 85 f6 0f 85 a4 01 00 00 48 c7 c0 90 33 93 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 <80> 3c 10 00 0f 85 2e 03 00 00 48 83 3d 9d 5b 38 08 00 0f 84 bb 02 RSP: 0018:ffffc9000f9c7530 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff1326672 RBX: 0000000000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff888044b30e94 RBP: ffffc9000f9c7578 R08: 0000000000000000 R09: 0000000000000000 R10: fffff9400013f018 R11: ffffea00009f80c7 R12: ffffffff899a3dc0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 rcu_lock_acquire include/linux/rcupdate.h:208 [inline] rcu_read_lock include/linux/rcupdate.h:617 [inline] aa_file_perm+0x17a/0x1600 security/apparmor/file.c:620 common_file_perm+0x1f1/0x940 security/apparmor/lsm.c:466 apparmor_file_permission+0x27/0x30 security/apparmor/lsm.c:480 security_file_permission+0x79/0x380 security/security.c:1375 rw_verify_area+0x11e/0x360 fs/read_write.c:399 do_iter_write+0x100/0x610 fs/read_write.c:965 vfs_iter_write+0x77/0xb0 fs/read_write.c:983 iter_file_splice_write+0x717/0xc10 fs/splice.c:760 do_splice_from fs/splice.c:863 [inline] direct_splice_actor+0x123/0x190 fs/splice.c:1037 splice_direct_to_actor+0x3b4/0xa30 fs/splice.c:992 do_splice_direct+0x1da/0x2a0 fs/splice.c:1080 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+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b349 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:00007f9b4c0c1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f9b4c0c26d4 RCX: 000000000045b349 RDX: 0000000000000000 RSI: 000000000000000c RDI: 000000000000000b RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00008000fffffffe R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008a6 R14: 00000000004ca018 R15: 000000000075bf2c rcu: rcu_preempt kthread starved for 10558 jiffies! g53857 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:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0x9b2/0x18d0 kernel/rcu/tree.c:1821 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352