rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7751/2:b..l P10625 (detected by 1, t=10503 jiffies, g=54689, q=543 ncpus=2) task:syz.1.2615 state:R running task stack:22008 pid:10625 ppid:10422 flags:0x00004008 Call Trace: sched_show_task+0x4d5/0x670 kernel/sched/core.c:8942 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:261 [inline] print_other_cpu_stall+0x1299/0x1640 kernel/rcu/tree_stall.h:606 check_cpu_stall kernel/rcu/tree_stall.h:778 [inline] rcu_pending kernel/rcu/tree.c:3890 [inline] rcu_sched_clock_irq+0xaf6/0x1200 kernel/rcu/tree.c:2393 update_process_times+0x147/0x1b0 kernel/time/timer.c:1869 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1501 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x5a7/0xe50 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x3e/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:dst_alloc+0x3f/0x190 net/core/dst.c:83 Code: ce 41 89 d5 48 89 74 24 10 49 89 ff 48 bb 00 00 00 00 00 fc ff df e8 60 77 ec f8 49 8d 6f 08 48 89 e8 48 c1 e8 03 80 3c 18 00 <74> 08 48 89 ef e8 67 f3 43 f9 4c 8b 65 00 8b 6c 24 0c 83 e5 08 31 RSP: 0018:ffffc900001e07e8 EFLAGS: 00000246 RAX: 1ffff1100ec38121 RBX: dffffc0000000000 RCX: ffff888023a1d940 RDX: 0000000000000101 RSI: ffff88807e91c000 RDI: ffff8880761c0900 RBP: ffff8880761c0908 R08: 0000000000000000 R09: fffffbfff1d33896 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88805a277c38 R13: 0000000000000001 R14: 00000000ffffffff R15: ffff8880761c0900 ip6_dst_alloc net/ipv6/route.c:345 [inline] icmp6_dst_alloc+0x7b/0x470 net/ipv6/route.c:3269 ndisc_send_skb+0x344/0x14e0 net/ipv6/ndisc.c:489 addrconf_rs_timer+0x357/0x610 net/ipv6/addrconf.c:3963 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571 __do_softirq kernel/softirq.c:605 [inline] invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:preempt_schedule_irq+0xf2/0x1c0 kernel/sched/core.c:6870 Code: 89 f5 49 c1 ed 03 eb 0d 48 f7 03 08 00 00 00 0f 84 97 00 00 00 bf 01 00 00 00 e8 69 a4 b0 f6 e8 d4 a2 e3 f6 fb bf 01 00 00 00 79 b4 ff ff 43 80 7c 3d 00 00 74 08 4c 89 f7 e8 69 5c 34 f7 48 RSP: 0018:ffffc900171066c0 EFLAGS: 00000282 RAX: 8a00df48b0d07400 RBX: 1ffff92002e20ce0 RCX: ffffffff816adfda RDX: dffffc0000000000 RSI: ffffffff8b0c0260 RDI: 0000000000000001 RBP: ffffc90017106780 R08: dffffc0000000000 R09: fffffbfff20e725c R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92002e20cd8 R13: 1ffff92002e20cdc R14: ffffc900171066e0 R15: dffffc0000000000 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 Code: 2b 00 74 08 4c 89 f7 e8 9f a8 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90017106840 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92002e20d14 RCX: 1ffff92002e20cb4 RDX: dffffc0000000000 RSI: ffffffff8b0c13e0 RDI: ffffffff8b5d5de0 RBP: ffffc90017106988 R08: dffffc0000000000 R09: fffffbfff20e7245 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92002e20d10 R13: dffffc0000000000 R14: ffffc900171068a0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] ipv6_addr_label+0x49/0x1d0 net/ipv6/addrlabel.c:148 ipv6_get_saddr_eval+0x5b7/0xe90 net/ipv6/addrconf.c:1623 __ipv6_dev_get_saddr+0x1d3/0x4a0 net/ipv6/addrconf.c:1712 ipv6_dev_get_saddr+0x417/0xbc0 net/ipv6/addrconf.c:1848 ip6_route_get_saddr include/net/ip6_route.h:145 [inline] ip6_dst_lookup_tail+0xcd4/0x11f0 net/ipv6/ip6_output.c:1121 ip6_dst_lookup_flow+0xb5/0x170 net/ipv6/ip6_output.c:1246 sctp_v6_get_dst+0x950/0x1e40 net/sctp/ipv6.c:327 sctp_transport_route+0x10c/0x2b0 net/sctp/transport.c:455 sctp_packet_config+0x432/0xd90 net/sctp/output.c:103 sctp_packet_singleton+0x149/0x320 net/sctp/outqueue.c:777 sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline] sctp_outq_flush+0x693/0x3d70 net/sctp/outqueue.c:1212 sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x55e7/0x5c80 net/sctp/sm_sideeffect.c:1170 sctp_primitive_ASSOCIATE+0x91/0xc0 net/sctp/primitive.c:73 sctp_sendmsg_to_asoc+0x1025/0x1910 net/sctp/socket.c:1839 sctp_sendmsg+0x1f49/0x3370 net/sctp/socket.c:2029 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514 ___sys_sendmsg net/socket.c:2568 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2597 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fed7bd779f9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fed7ca9e048 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fed7bf05f80 RCX: 00007fed7bd779f9 RDX: 00000000040080c0 RSI: 00000000200003c0 RDI: 0000000000000008 RBP: 00007fed7bde58ee R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fed7bf05f80 R15: 00007ffee661ac98 task:kworker/1:14 state:R running task stack:24040 pid:7751 ppid:2 flags:0x00004000 Workqueue: mld mld_ifc_work Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __local_bh_enable_ip+0x175/0x1f0 kernel/softirq.c:403 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:861 [inline] __dev_queue_xmit+0x1790/0x3cf0 net/core/dev.c:4320 dev_queue_xmit include/linux/netdevice.h:3021 [inline] neigh_hh_output include/net/neighbour.h:528 [inline] neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0xea9/0x1530 net/ipv6/ip6_output.c:134 __ip6_finish_output net/ipv6/ip6_output.c:201 [inline] ip6_finish_output+0x6a0/0xa80 net/ipv6/ip6_output.c:212 dst_output include/net/dst.h:444 [inline] NF_HOOK+0x167/0x530 include/linux/netfilter.h:302 mld_sendpack+0x85e/0xde0 net/ipv6/mcast.c:1820 mld_send_cr net/ipv6/mcast.c:2121 [inline] mld_ifc_work+0x7d7/0xc90 net/ipv6/mcast.c:2653 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10510 jiffies! g54689 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:I stack:26472 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4147 Comm: kworker/u4:6 Not tainted 6.1.103-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0x1fb0/0x3460 kernel/smp.c:998 Code: 2f 44 89 ee 83 e6 01 31 ff e8 4c 40 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 d7 3c 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff RSP: 0018:ffffc900172ae120 EFLAGS: 00000293 RAX: ffffffff817f63eb RBX: 1ffff110173281b1 RCX: ffff88801b6e9dc0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900172ae500 R08: ffffffff817f63b4 R09: ffffed1017307753 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b9940d88 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feda94960a8 CR3: 000000004e0c0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline] flush_tlb_multi arch/x86/mm/tlb.c:924 [inline] flush_tlb_mm_range+0x353/0x590 arch/x86/mm/tlb.c:1010 flush_tlb_page arch/x86/include/asm/tlbflush.h:240 [inline] ptep_clear_flush+0x116/0x160 mm/pgtable-generic.c:98 page_vma_mkclean_one+0x569/0x930 mm/rmap.c:970 page_mkclean_one+0x2f8/0x4c0 mm/rmap.c:1018 rmap_walk_file+0x369/0x740 mm/rmap.c:2511 rmap_walk mm/rmap.c:2529 [inline] folio_mkclean+0x250/0x430 mm/rmap.c:1050 folio_clear_dirty_for_io+0x229/0xcf0 mm/page-writeback.c:2886 mpage_submit_page+0x90/0x230 fs/ext4/inode.c:2110 mpage_process_page_bufs+0x6c8/0x8b0 fs/ext4/inode.c:2244 mpage_prepare_extent_to_map+0xb82/0x1730 fs/ext4/inode.c:2669 ext4_writepages+0xcc8/0x3de0 fs/ext4/inode.c:2797 do_writepages+0x3a2/0x670 mm/page-writeback.c:2491 __writeback_single_inode+0x15d/0x11e0 fs/fs-writeback.c:1612 writeback_sb_inodes+0xc2b/0x1b20 fs/fs-writeback.c:1903 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:1974 wb_writeback+0x4b1/0xe10 fs/fs-writeback.c:2079 wb_check_old_data_flush fs/fs-writeback.c:2179 [inline] wb_do_writeback fs/fs-writeback.c:2232 [inline] wb_workfn+0xbec/0x1020 fs/fs-writeback.c:2260 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295