syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=582/1/0x4000000000000000 softirq=107187/107188 fqs=0 
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1):
	(detected by 1, t=10502 jiffies, g=183537, q=42)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 12586 Comm: syz-executor.4 Not tainted 5.13.0-rc2-next-20210518-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:91 [inline]
RIP: 0010:lock_release+0x124/0x720 kernel/locking/lockdep.c:5525
Code: 85 e8 02 00 00 65 4c 8b 34 25 00 f0 01 00 49 8d be 24 0a 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 69 05 00 00 45
RSP: 0018:ffffc900000074c0 EFLAGS: 00000803
RAX: dffffc0000000000 RBX: ffffffff8de9f76c RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000010104 RDI: ffff88801fe54324
RBP: 1ffff92000000e9a R08: 0000000000000000 R09: ffffffff8de9c4d7
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff90b8eea0
R13: ffffffff898dade0 R14: ffff88801fe53900 R15: ffff88801cd4b340
FS:  00007fc8aa72d700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000970004 CR3: 0000000077e4e000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline]
 _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:191
 debug_object_deactivate lib/debugobjects.c:752 [inline]
 debug_object_deactivate+0x264/0x300 lib/debugobjects.c:718
 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline]
 debug_deactivate kernel/time/hrtimer.c:481 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1505 [inline]
 __hrtimer_run_queues+0x3f8/0xe50 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
RIP: 0010:update_sd_lb_stats.constprop.0+0xd6e/0x2960 kernel/sched/fair.c:9021
Code: b6 14 28 48 c7 c0 a4 c6 e9 8d 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 ef 18 00 00 8b 05 ce f5 94 0c 89 04 24 e9 22 f5 ff ff <48> 8b 44 24 40 48 8d 78 08 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f
RSP: 0018:ffffc90000007918 EFLAGS: 00000247
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8154c51a
RDX: ffffed10024830e5 RSI: 0000000000000008 RDI: ffff888012418720
RBP: ffff888012418720 R08: 0000000000000000 R09: ffff888012418727
R10: ffffed10024830e4 R11: 0000000000000001 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffc90000007d90 R15: 0000000000000000
 find_busiest_group+0x9a/0x8c0 kernel/sched/fair.c:9279
 load_balance+0x37d/0x2900 kernel/sched/fair.c:9661
 rebalance_domains+0x668/0xda0 kernel/sched/fair.c:10078
 __do_softirq+0x29b/0x9fb kernel/softirq.c:559
 invoke_softirq kernel/softirq.c:433 [inline]
 __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:85 [inline]
RIP: 0010:lock_release+0xe7/0x720 kernel/locking/lockdep.c:5525
Code: fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 5b 05 00 00 44 8b 15 35 9c 8e 0c <45> 85 d2 0f 84 f7 02 00 00 65 8b 05 f9 9e a6 7e 85 c0 0f 85 e8 02
RSP: 0018:ffffc90003fc7778 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffffffff8de9f76c RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 1ffff920007f8ef1 R08: 0000000000000000 R09: ffffffff8de9c4d7
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88809a001200
R13: 0000000000000001 R14: 0000000000000000 R15: ffff88807378094c
 __raw_read_unlock include/linux/rwlock_api_smp.h:225 [inline]
 _raw_read_unlock+0x12/0x40 kernel/locking/spinlock.c:255
 ext4_es_lookup_extent+0x4a6/0xcf0 fs/ext4/extents_status.c:983
 ext4_map_blocks+0x1f1/0x17d0 fs/ext4/inode.c:530
 ext4_getblk+0x52b/0x680 fs/ext4/inode.c:848
 ext4_bread_batch+0x7c/0x5a0 fs/ext4/inode.c:921
 __ext4_find_entry+0x482/0x1050 fs/ext4/namei.c:1597
 ext4_lookup_entry fs/ext4/namei.c:1698 [inline]
 ext4_lookup fs/ext4/namei.c:1766 [inline]
 ext4_lookup+0x4fc/0x730 fs/ext4/namei.c:1757
 __lookup_hash+0x117/0x180 fs/namei.c:1530
 filename_create+0x186/0x490 fs/namei.c:3593
 user_path_create fs/namei.c:3650 [inline]
 do_mkdirat+0xa0/0x310 fs/namei.c:3828
 do_syscall_64+0x31/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4656e7
Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc8aa72cfa8 EFLAGS: 00000213 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 0000000020000300 RCX: 00000000004656e7
RDX: 0000000000000004 RSI: 00000000000001ff RDI: 0000000020000100
RBP: 00007fc8aa72d040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000213 R12: 00000000200000c0
R13: 0000000020000100 R14: 00007fc8aa72d000 R15: 0000000020000380
task:kworker/u4:3    state:R  running task     stack:24984 pid:  143 ppid:     2 flags:0x00004000
Workqueue: krdsd rds_shutdown_worker
Call Trace:
 context_switch kernel/sched/core.c:4688 [inline]
 __schedule+0xb38/0x58c0 kernel/sched/core.c:5945
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6105
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 __local_bh_enable_ip+0x109/0x120 kernel/softirq.c:391
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:757 [inline]
 ip6_finish_output2+0x6d4/0x1700 net/ipv6/ip6_output.c:118
 __ip6_finish_output net/ipv6/ip6_output.c:182 [inline]
 __ip6_finish_output+0x4c1/0xe10 net/ipv6/ip6_output.c:161
 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:192
 NF_HOOK_COND include/linux/netfilter.h:290 [inline]
 ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:215
 dst_output include/net/dst.h:448 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 NF_HOOK include/linux/netfilter.h:295 [inline]
 ip6_xmit+0x1277/0x1ea0 net/ipv6/ip6_output.c:320
 inet6_csk_xmit+0x333/0x630 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x1889/0x38f0 net/ipv4/tcp_output.c:1405
 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline]
 tcp_write_xmit+0xdee/0x6050 net/ipv4/tcp_output.c:2689
 __tcp_push_pending_frames+0xaa/0x390 net/ipv4/tcp_output.c:2873
 tcp_send_fin+0x117/0xbb0 net/ipv4/tcp_output.c:3422
 __tcp_close+0xaca/0x1170 net/ipv4/tcp.c:2790
 tcp_close+0x29/0xc0 net/ipv4/tcp.c:2880
 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431
 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:478
 __sock_release net/socket.c:599 [inline]
 sock_release+0x87/0x1b0 net/socket.c:627
 rds_tcp_conn_path_shutdown+0x1eb/0x3f0 net/rds/tcp_connect.c:216
 rds_conn_shutdown+0x248/0x930 net/rds/connection.c:386
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
rcu: rcu_preempt kthread starved for 10502 jiffies! g183537 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27848 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4688 [inline]
 __schedule+0xb38/0x58c0 kernel/sched/core.c:5945
 schedule+0xcf/0x270 kernel/sched/core.c:6024
 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1878
 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline]
 rcu_gp_kthread+0xd21/0x1960 kernel/rcu/tree.c:2169
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 12592 Comm: syz-executor.2 Not tainted 5.13.0-rc2-next-20210518-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x13e/0x1d6 lib/dump_stack.c:129
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation.cold+0x1cc/0x1d1 kernel/rcu/tree_stall.h:479
 print_other_cpu_stall kernel/rcu/tree_stall.h:584 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:709 [inline]
 rcu_pending kernel/rcu/tree.c:3922 [inline]
 rcu_sched_clock_irq+0x1d46/0x2080 kernel/rcu/tree.c:2641
 update_process_times+0x16d/0x200 kernel/time/timer.c:1782
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1420
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:967
Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 a0 43 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31
RSP: 0018:ffffc900042a7cb0 EFLAGS: 00000246
RAX: 0000000000040000 RBX: ffff8880b9c3c400 RCX: ffffc9000dffc000
RDX: 0000000000040000 RSI: ffffffff816a9030 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff816a9056 R11: 0000000000000000 R12: ffffed1017387881
R13: 0000000000000000 R14: ffff8880b9c3c408 R15: 0000000000000001
 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1133
 on_each_cpu include/linux/smp.h:71 [inline]
 clock_was_set+0x21/0x30 kernel/time/hrtimer.c:889
 do_settimeofday64 kernel/time/timekeeping.c:1327 [inline]
 do_settimeofday64+0x3dd/0x5c0 kernel/time/timekeeping.c:1293
 do_sys_settimeofday64 kernel/time/time.c:195 [inline]
 do_sys_settimeofday64+0x1de/0x260 kernel/time/time.c:169
 __do_sys_clock_settime kernel/time/posix-timers.c:1079 [inline]
 __se_sys_clock_settime kernel/time/posix-timers.c:1067 [inline]
 __x64_sys_clock_settime+0x1a1/0x280 kernel/time/posix-timers.c:1067
 do_syscall_64+0x31/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3777d51188 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000000
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007fffba49d87f R14: 00007f3777d51300 R15: 0000000000022000