rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=16245, q=46) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294973537-4294963034), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.1 R running task 26296 10908 9089 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:__sanitizer_cov_trace_pc+0x1/0x50 kernel/kcov.c:95 Code: 25 74 ce 16 09 41 bc f4 ff ff ff e8 ad a6 e9 ff 48 c7 05 5e ce 16 09 00 00 00 00 e9 77 e9 ff ff 90 90 90 90 90 90 90 90 90 55 <48> 89 e5 65 48 8b 04 25 c0 fd 01 00 65 8b 15 c4 a9 8f 7e 81 e2 00 RSP: 0018:ffff88805eeb7248 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000002 RBX: 0000000000000004 RCX: ffffffff818e092b RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff88805eeb7340 R08: ffff88808c0ae240 R09: ffffed100bdd6e54 R10: ffffed100bdd6e53 R11: 0000000000000003 R12: ffffea0001e08880 R13: ffffea0001e088b4 R14: ffff88805eeb7318 R15: 0000000000000001 pagecache_get_page+0x4c/0x880 mm/filemap.c:1608 grab_cache_page_write_begin+0x75/0xb0 mm/filemap.c:3225 ext4_da_write_begin+0x2ec/0xb70 fs/ext4/inode.c:3085 generic_perform_write+0x23b/0x530 mm/filemap.c:3275 __generic_file_write_iter+0x25e/0x630 mm/filemap.c:3404 ext4_file_write_iter+0x373/0x1430 fs/ext4/file.c:270 call_write_iter include/linux/fs.h:1870 [inline] do_iter_readv_writev+0x5f8/0x8f0 fs/read_write.c:693 do_iter_write fs/read_write.c:970 [inline] do_iter_write+0x184/0x610 fs/read_write.c:951 vfs_iter_write+0x77/0xb0 fs/read_write.c:983 iter_file_splice_write+0x66d/0xbe0 fs/splice.c:746 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:00007f6903e35c78 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: 00007f6903e366d4 R13: 00000000004c6def R14: 00000000004dc128 R15: 00000000ffffffff rcu: rcu_preempt kthread starved for 10559 jiffies! g16245 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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