rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P26779/2:b..l rcu: (detected by 1, t=10502 jiffies, g=188413, q=897 ncpus=2) task:syz-executor.1 state:R running task stack:25344 pid:26779 ppid:25066 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 preempt_schedule_common+0x45/0xb0 kernel/sched/core.c:6838 preempt_schedule_thunk+0x1a/0x20 arch/x86/entry/thunk_64.S:34 __local_bh_enable_ip+0x10d/0x130 kernel/softirq.c:403 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:843 [inline] __dev_queue_xmit+0x1e20/0x3b10 net/core/dev.c:4271 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_hh_output include/net/neighbour.h:528 [inline] neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0xfbd/0x1560 net/ipv6/ip6_output.c:134 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline] ip6_finish_output+0x69a/0x1170 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:458 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] NF_HOOK include/linux/netfilter.h:297 [inline] ip6_xmit+0x11e5/0x1c80 net/ipv6/ip6_output.c:343 inet6_csk_xmit+0x3b4/0x730 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x194b/0x3800 net/ipv4/tcp_output.c:1399 tcp_transmit_skb net/ipv4/tcp_output.c:1417 [inline] tcp_write_xmit+0x1025/0x6160 net/ipv4/tcp_output.c:2693 __tcp_push_pending_frames+0xae/0x390 net/ipv4/tcp_output.c:2877 tcp_push+0x49d/0x720 net/ipv4/tcp.c:733 do_tcp_sendpages+0x1ac4/0x1ea0 net/ipv4/tcp.c:1119 tcp_sendpage_locked net/ipv4/tcp.c:1145 [inline] tcp_sendpage_locked net/ipv4/tcp.c:1137 [inline] tcp_sendpage+0x84/0xd0 net/ipv4/tcp.c:1155 inet_sendpage+0xd4/0x140 net/ipv4/af_inet.c:844 kernel_sendpage.part.0+0x1d5/0x700 net/socket.c:3582 kernel_sendpage net/socket.c:3579 [inline] sock_sendpage+0xe7/0x180 net/socket.c:1082 pipe_to_sendpage+0x2b1/0x380 fs/splice.c:471 splice_from_pipe_feed fs/splice.c:525 [inline] __splice_from_pipe+0x449/0x8a0 fs/splice.c:669 splice_from_pipe fs/splice.c:704 [inline] generic_splice_sendpage+0xd8/0x140 fs/splice.c:852 do_splice_from fs/splice.c:873 [inline] direct_splice_actor+0x114/0x180 fs/splice.c:1039 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:994 do_splice_direct+0x1ab/0x280 fs/splice.c:1082 do_sendfile+0xb19/0x12c0 fs/read_write.c:1254 __do_sys_sendfile64 fs/read_write.c:1322 [inline] __se_sys_sendfile64 fs/read_write.c:1308 [inline] __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1308 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fc9a088c169 RSP: 002b:00007fc9a1640168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fc9a09ac120 RCX: 00007fc9a088c169 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005 RBP: 00007fc9a08e7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000080000004 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc9a0acfb1f R14: 00007fc9a1640300 R15: 0000000000022000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10438 jiffies! g188413 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=163123 rcu: rcu_preempt kthread starved for 10444 jiffies! g188413 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28312 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 schedule_timeout+0x14e/0x2b0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1808 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 26777 Comm: syz-executor.1 Not tainted 6.4.0-rc5-syzkaller-00024-g5f63595ebd82 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 RIP: 0010:__list_add_valid+0x71/0x100 lib/list_debug.c:39 Code: 00 00 00 00 fc ff df 48 89 f2 48 c1 ea 03 80 3c 02 00 75 77 48 8b 16 4c 39 e2 75 44 48 39 f5 74 53 4c 39 e5 74 4e 48 83 c4 08 01 00 00 00 5d 41 5c c3 48 c7 c7 c0 13 a7 8a e8 fa d2 50 fd 0f RSP: 0018:ffffc900001e0608 EFLAGS: 00000282 RAX: dffffc0000000000 RBX: ffff888034fba290 RCX: 0000000000000100 RDX: ffff88804459f2e0 RSI: ffff88804459f2e0 RDI: ffff88804459f2e8 RBP: ffff888034fba290 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0200000000000000 R12: ffff88804459f2e0 R13: ffff88804459f2e0 R14: ffff88804459f2f0 R15: ffff88804459f2e0 FS: 00007fc9a1661700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000201c8000 CR3: 00000000792df000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000003b DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __list_add include/linux/list.h:69 [inline] list_add_tail include/linux/list.h:102 [inline] list_move_tail include/linux/list.h:230 [inline] fq_pie_qdisc_dequeue+0x70e/0x9c0 net/sched/sch_fq_pie.c:248 dequeue_skb net/sched/sch_generic.c:292 [inline] qdisc_restart net/sched/sch_generic.c:397 [inline] __qdisc_run+0x1b2/0x1780 net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3868 [inline] __dev_queue_xmit+0x2215/0x3b10 net/core/dev.c:4210 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_connected_output+0x3c2/0x550 net/core/neighbour.c:1581 neigh_output include/net/neighbour.h:544 [inline] ip6_finish_output2+0x55a/0x1560 net/ipv6/ip6_output.c:134 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline] ip6_finish_output+0x69a/0x1170 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:458 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ndisc_send_skb+0xa63/0x1850 net/ipv6/ndisc.c:508 ndisc_send_rs+0x132/0x6f0 net/ipv6/ndisc.c:718 addrconf_rs_timer+0x3f1/0x870 net/ipv6/addrconf.c:3936 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers+0x29b/0x4b0 kernel/time/timer.c:1751 __run_timers kernel/time/timer.c:2022 [inline] __run_timers kernel/time/timer.c:1995 [inline] run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035 __do_softirq+0x1d4/0x905 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x114/0x190 kernel/softirq.c:650 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:xas_nomem+0x0/0x2c0 lib/xarray.c:301 Code: df fe ff ff 48 c7 c7 40 ae 1c 92 48 89 34 24 e8 46 4c d3 f7 48 8b 34 24 e9 e9 fe ff ff 4c 89 ff e8 d5 4c d3 f7 e9 16 ff ff ff 0f 1e fa 41 57 41 56 41 55 41 54 41 89 f4 55 48 89 fd 53 4c 8d RSP: 0018:ffffc9000385f8d8 EFLAGS: 00000286 RAX: 0000000080000000 RBX: ffffc9000385f940 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000cc0 RDI: ffffc9000385f940 RBP: ffffea0001534ec0 R08: 0000000000000001 R09: ffffffff91529da7 R10: 0000000000000001 R11: 0000000000094001 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000cc0 shmem_add_to_page_cache+0x817/0xd50 mm/shmem.c:747 shmem_get_folio_gfp+0x58a/0x1a80 mm/shmem.c:1978 shmem_get_folio mm/shmem.c:2079 [inline] shmem_write_begin+0x14a/0x380 mm/shmem.c:2573 generic_perform_write+0x256/0x570 mm/filemap.c:3923 __generic_file_write_iter+0x2ae/0x500 mm/filemap.c:4051 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4083 call_write_iter include/linux/fs.h:1868 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x945/0xd50 fs/read_write.c:584 ksys_write+0x12b/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fc9a088c169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc9a1661168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc9a09ac050 RCX: 00007fc9a088c169 RDX: 00000000fffffd9d RSI: 00000000200001c0 RDI: 0000000000000006 RBP: 00007fc9a08e7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc9a0acfb1f R14: 00007fc9a1661300 R15: 0000000000022000