rcu: INFO: rcu_sched detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=157, q=1) rcu: All QSes seen, last rcu_sched kthread activity 10500 (4294963744-4294953244), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.5 R running task 26320 13016 8131 0x00000000 Call Trace: sched_show_task kernel/sched/core.c:5338 [inline] sched_show_task.cold+0x2e2/0x343 kernel/sched/core.c:5313 print_other_cpu_stall kernel/rcu/tree.c:1430 [inline] check_cpu_stall kernel/rcu/tree.c:1557 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0xaf0/0xddc kernel/rcu/tree.c:2682 update_process_times+0x2a/0x70 kernel/time/timer.c:1638 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168 tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x2fc/0xd50 kernel/time/hrtimer.c:1463 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1521 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:copy_page_to_iter+0x2/0xdc0 lib/iov_iter.c:844 Code: 48 8b 7c 24 38 e8 ae f4 49 fe e9 e2 f9 ff ff 48 8b 7c 24 28 e8 1f f4 49 fe e9 ad f9 ff ff 66 2e 0f 1f 84 00 00 00 00 00 41 57 <41> 56 41 55 49 89 fd 41 54 49 89 cc 55 48 89 d5 53 48 89 f3 48 83 RSP: 0018:ffff8880617ef800 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: 0000000000000b10 RCX: ffff8880617efa48 RDX: 000000000000007e RSI: 0000000000000b10 RDI: ffffea0001444180 RBP: 000000000000007e R08: ffff8880892921c0 R09: ffffed101295d939 R10: ffffed101295d938 R11: ffff888094aec9c3 R12: ffff888094aec9c0 R13: 0000000000000b10 R14: dffffc0000000000 R15: ffffea0001444180 generic_file_buffered_read mm/filemap.c:2208 [inline] generic_file_read_iter+0x8b3/0x2810 mm/filemap.c:2385 ext4_file_read_iter+0x17b/0x3a0 fs/ext4/file.c:78 call_read_iter include/linux/fs.h:1814 [inline] generic_file_splice_read+0x3fa/0x6d0 fs/splice.c:308 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a8/0x270 fs/splice.c:1068 do_sendfile+0x549/0xc10 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1502 [inline] __se_sys_sendfile64 fs/read_write.c:1494 [inline] __x64_sys_sendfile64+0x149/0x210 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 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:00007fd82758bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fd82758c6d4 RCX: 000000000045c849 RDX: 00000000200001c0 RSI: 0000000000000008 RDI: 0000000000000008 RBP: 000000000076c040 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d0 R14: 00000000004cb74a R15: 000000000076c04c rcu: rcu_sched kthread starved for 10500 jiffies! g157 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_sched R running task 29744 11 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x4d1/0xf20 kernel/time/timer.c:1806 rcu_gp_kthread+0xcee/0x2060 kernel/rcu/tree.c:2202 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10548 jiffies, g=24737, q=50) rcu: All QSes seen, last rcu_preempt kthread activity 10548 (4294963792-4294953244), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.5 R running task 26320 13016 8131 0x80000000 Call Trace: sched_show_task kernel/sched/core.c:5338 [inline] sched_show_task.cold+0x2e2/0x343 kernel/sched/core.c:5313 print_other_cpu_stall kernel/rcu/tree.c:1430 [inline] check_cpu_stall kernel/rcu/tree.c:1557 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0xaf0/0xddc kernel/rcu/tree.c:2682 update_process_times+0x2a/0x70 kernel/time/timer.c:1638 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168 tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x2fc/0xd50 kernel/time/hrtimer.c:1463 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1521 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:copy_page_to_iter+0x2/0xdc0 lib/iov_iter.c:844 Code: 48 8b 7c 24 38 e8 ae f4 49 fe e9 e2 f9 ff ff 48 8b 7c 24 28 e8 1f f4 49 fe e9 ad f9 ff ff 66 2e 0f 1f 84 00 00 00 00 00 41 57 <41> 56 41 55 49 89 fd 41 54 49 89 cc 55 48 89 d5 53 48 89 f3 48 83 RSP: 0018:ffff8880617ef800 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: 0000000000000b10 RCX: ffff8880617efa48 RDX: 000000000000007e RSI: 0000000000000b10 RDI: ffffea0001444180 RBP: 000000000000007e R08: ffff8880892921c0 R09: ffffed101295d939 R10: ffffed101295d938 R11: ffff888094aec9c3 R12: ffff888094aec9c0 R13: 0000000000000b10 R14: dffffc0000000000 R15: ffffea0001444180 generic_file_buffered_read mm/filemap.c:2208 [inline] generic_file_read_iter+0x8b3/0x2810 mm/filemap.c:2385 ext4_file_read_iter+0x17b/0x3a0 fs/ext4/file.c:78 call_read_iter include/linux/fs.h:1814 [inline] generic_file_splice_read+0x3fa/0x6d0 fs/splice.c:308 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a8/0x270 fs/splice.c:1068 do_sendfile+0x549/0xc10 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1502 [inline] __se_sys_sendfile64 fs/read_write.c:1494 [inline] __x64_sys_sendfile64+0x149/0x210 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 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:00007fd82758bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fd82758c6d4 RCX: 000000000045c849 RDX: 00000000200001c0 RSI: 0000000000000008 RDI: 0000000000000008 RBP: 000000000076c040 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d0 R14: 00000000004cb74a R15: 000000000076c04c rcu: rcu_preempt kthread starved for 10548 jiffies! g24737 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29056 10 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x4d1/0xf20 kernel/time/timer.c:1806 rcu_gp_kthread+0xcee/0x2060 kernel/rcu/tree.c:2202 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415