rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7983/2:b..l P7991/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=25449, q=332 ncpus=2)
task:syz.2.731       state:R  running task     stack:21248 pid:7991  tgid:7985  ppid:5226   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:867 [inline]
RIP: 0010:count_memcg_event_mm+0x334/0x420 include/linux/memcontrol.h:1021
Code: d2 2a b5 ff 4c 8b 6c 24 18 eb 1f e8 c6 2a b5 ff e8 d1 ee ce 09 4d 85 f6 74 84 e8 b7 2a b5 ff fb 49 be 00 00 00 00 00 fc ff df <e8> 57 f5 ce 09 89 c3 31 ff 89 c6 e8 dc 2e b5 ff 85 db 74 10 e8 33
RSP: 0018:ffffc9001614f5e0 EFLAGS: 00000283
RAX: ffffffff81de4b99 RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc9000a2be000 RSI: 000000000000a5c0 RDI: 000000000000a5c1
RBP: ffffc9001614f6b0 R08: ffffffff81de4b09 R09: 1ffffffff269dd06
R10: dffffc0000000000 R11: fffffbfff269dd07 R12: 0000000000000046
R13: ffffffff81de4904 R14: dffffc0000000000 R15: 1ffff92002c29ec0
 mm_account_fault mm/memory.c:5699 [inline]
 handle_mm_fault+0x149a/0x1880 mm/memory.c:5859
 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:fault_in_readable+0x165/0x2b0 mm/gup.c:2244
Code: b7 ff 4c 8d b3 ff 0f 00 00 48 89 d8 4d 01 e6 49 81 e6 00 f0 ff ff 49 39 c6 72 6b e8 55 aa b7 ff 4c 39 f3 74 6e 4c 89 64 24 10 <44> 8a 23 43 0f b6 04 2f 84 c0 75 18 44 88 64 24 40 48 81 c3 00 10
RSP: 0018:ffffc9001614fa20 EFLAGS: 00050287
RAX: ffffffff81dbcc27 RBX: 0000000020197000 RCX: 0000000000040000
RDX: ffffc9000a2be000 RSI: 000000000000a559 RDI: 000000000000a55a
RBP: ffffc9001614fad8 R08: ffffffff81dbcb98 R09: ffffffff84a54879
R10: 0000000000000002 R11: ffff888023743c00 R12: 0000000000200000
R13: dffffc0000000000 R14: 0000000020201000 R15: 1ffff92002c29f4c
 fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94
 generic_perform_write+0x29f/0x840 mm/filemap.c:4009
 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:3078
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa72/0xc90 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb3809779f9
RSP: 002b:00007fb3803de048 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb380b06058 RCX: 00007fb3809779f9
RDX: 00000000fffffd9d RSI: 0000000020000200 RDI: 000000000000000a
RBP: 00007fb3809e58ee R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb380b06058 R15: 00007ffccaac6348
 </TASK>
task:syz.4.729       state:R  running task     stack:21040 pid:7983  tgid:7980  ppid:5232   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6708
 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6732
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __local_bh_enable_ip+0x179/0x200 kernel/softirq.c:389
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline]
 __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450
 dev_queue_xmit include/linux/netdevice.h:3105 [inline]
 neigh_hh_output include/net/neighbour.h:526 [inline]
 neigh_output include/net/neighbour.h:540 [inline]
 ip6_finish_output2+0xfc2/0x1680 net/ipv6/ip6_output.c:137
 ip6_finish_output+0x41e/0x810 net/ipv6/ip6_output.c:222
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip6_xmit+0xefe/0x17f0 net/ipv6/ip6_output.c:358
 inet6_csk_xmit+0x468/0x710 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x1ed1/0x3b30 net/ipv4/tcp_output.c:1466
 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline]
 tcp_write_xmit+0x18b4/0x6a10 net/ipv4/tcp_output.c:2829
 __tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:3014
 tcp_sendmsg_locked+0x27f9/0x4e10 net/ipv4/tcp.c:1300
 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1354
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0xef/0x270 net/socket.c:745
 sock_sendmsg+0x134/0x200 net/socket.c:768
 splice_to_socket+0xa13/0x10b0 fs/splice.c:889
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x11e/0x220 fs/splice.c:1164
 splice_direct_to_actor+0x58e/0xc90 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x28c/0x3e0 fs/splice.c:1233
 do_sendfile+0x56d/0xe20 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c63b779f9
RSP: 002b:00007f5c649b5048 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f5c63d06130 RCX: 00007f5c63b779f9
RDX: 0000000000000000 RSI: 000000000000000b RDI: 000000000000000a
RBP: 00007f5c63be58ee R08: 0000000000000000 R09: 0000000000000000
R10: 000000008000002b R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f5c63d06130 R15: 00007ffe3b17aef8
 </TASK>
rcu: rcu_preempt kthread starved for 10597 jiffies! g25449 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:26448 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111