rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5959/1:b..l P6076/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=11305, q=323 ncpus=2)
task:kworker/u8:13   state:R  running task     stack:26424 pid:6076  tgid:6076  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5258 [inline]
 __schedule+0x150e/0x5070 kernel/sched/core.c:6866
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:mod_node_state+0xa5/0x160 mm/vmstat.c:662
Code: 49 01 cc 4c 89 e7 48 f7 df 49 0f 48 fc 48 39 f7 7e 18 d0 fa 0f be d2 0f af d5 89 d6 40 f6 de 65 41 0f b0 74 1d 01 74 0d eb c9 <65> 45 0f b0 64 1d 01 74 45 eb be 48 63 c2 49 01 c4 74 3b 49 81 c6
RSP: 0018:ffffc900036076d8 EFLAGS: 00000287
RAX: 00000000000000f4 RBX: 0000000000000015 RCX: ffffffffffffffff
RDX: ffffffffffffff18 RSI: 0000000000000018 RDI: 000000000000000d
RBP: 0000000000000000 R08: ffffffff82309e1f R09: ffffffff8e33f2e0
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: fffffffffffffff3
R13: ffffffff92c65280 R14: ffff88813fffb400 R15: 0000000000000015
 mod_lruvec_state mm/memcontrol.c:773 [inline]
 lruvec_stat_mod_folio+0x187/0x2e0 mm/memcontrol.c:797
 __folio_end_writeback+0x576/0x770 mm/page-writeback.c:3009
 folio_end_writeback_no_dropbehind+0x151/0x290 mm/filemap.c:1661
 folio_end_writeback+0xea/0x220 mm/filemap.c:1687
 ext4_finish_bio+0x617/0x9b0 fs/ext4/page-io.c:144
 ext4_release_io_end+0xef/0x2c0 fs/ext4/page-io.c:159
 ext4_end_io_end+0x278/0x410 fs/ext4/page-io.c:210
 ext4_do_flush_completed_IO fs/ext4/page-io.c:290 [inline]
 ext4_end_io_rsv_work+0x262/0x330 fs/ext4/page-io.c:305
 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
 process_scheduled_works kernel/workqueue.c:3362 [inline]
 worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
task:syz-executor    state:R  running task     stack:19496 pid:5959  tgid:5959  ppid:5955   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5258 [inline]
 __schedule+0x150e/0x5070 kernel/sched/core.c:6866
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 44 91 25 11 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900033c6bd8 EFLAGS: 00000206
RAX: c6c9adb373f8eb00 RBX: 0000000000000000 RCX: c6c9adb373f8eb00
RDX: 000000000b90ca8a RSI: ffffffff8dc93c7b RDI: ffffffff8be247e0
RBP: ffffffff81746f85 R08: ffffffff81746f85 R09: ffffffff8e33f2e0
R10: ffffc900033c6d98 R11: ffffffff81addd50 R12: 0000000000000002
R13: ffffffff8e33f2e0 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 ref_tracker_alloc+0x17d/0x460 lib/ref_tracker.c:277
 __netdev_tracker_alloc include/linux/netdevice.h:4415 [inline]
 netdev_tracker_alloc include/linux/netdevice.h:4427 [inline]
 netdev_get_by_index+0x79/0xb0 net/core/dev.c:1008
 fib6_nh_init+0x1cd/0x2020 net/ipv6/route.c:3590
 ip6_route_info_create_nh+0x16a/0xab0 net/ipv6/route.c:3890
 ip6_route_add+0x6e/0x1b0 net/ipv6/route.c:3942
 addrconf_prefix_route net/ipv6/addrconf.c:2488 [inline]
 inet6_addr_add+0x75f/0xce0 net/ipv6/addrconf.c:3053
 inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5059
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737
 __sock_sendmsg net/socket.c:752 [inline]
 __sys_sendto+0x3ce/0x540 net/socket.c:2221
 __do_sys_sendto net/socket.c:2228 [inline]
 __se_sys_sendto net/socket.c:2224 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2224
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75285915dc
RSP: 002b:00007ffd8289ff00 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f7529314620 RCX: 00007f75285915dc
RDX: 0000000000000040 RSI: 00007f7529314670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffd8289ff54 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f7529314670 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10598 jiffies! g11305 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:27728 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5258 [inline]
 __schedule+0x150e/0x5070 kernel/sched/core.c:6866
 __schedule_loop kernel/sched/core.c:6948 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6963
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 0e 21 00 f3 0f 1e fa fb f4 <e9> 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 5a67d7e00f7e0000 RBX: ffffffff8197c6ba RCX: 5a67d7e00f7e0000
RDX: 0000000000000001 RSI: ffffffff8daa9dc3 RDI: ffffffff8be247e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fc3d070
R13: 1ffff11003adcb70 R14: 0000000000000001 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f780d9b6ad8 CR3: 0000000031888000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x1ea/0x520 kernel/sched/idle.c:332
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x147
 </TASK>