rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3423/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=9781, q=82 ncpus=2)
task:kworker/u8:9    state:R  running task     stack:21080 pid:3423  tgid:3423  ppid:2      task_flags:0x24248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5282 [inline]
 __schedule+0x14ed/0x5040 kernel/sched/core.c:6894
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221
 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:xas_move_index lib/xarray.c:158 [inline]
RIP: 0010:xas_next_offset lib/xarray.c:166 [inline]
RIP: 0010:xas_find+0x2dc/0x990 lib/xarray.c:1414
Code: 44 24 20 4c 8b 33 4c 89 f0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 db 05 00 00 41 0f b6 2e bf 40 00 00 00 89 ee e8 24 b8 5b f6 <83> fd 3f 0f 87 dd 05 00 00 e8 16 b5 5b f6 49 c7 c4 c0 ff ff ff 89
RSP: 0018:ffffc9000bafeb90 EFLAGS: 00000293
RAX: ffffffff8b65459c RBX: ffffc9000bafec78 RCX: 0000000000000000
RDX: ffff8880312adac0 RSI: 0000000000000000 RDI: 0000000000000040
RBP: 0000000000000000 R08: ffff8880312adac0 R09: 0000000000000002
R10: 0000000000000003 R11: 0000000000000000 R12: ffffc9000bafec60
R13: dffffc0000000000 R14: ffff888025c6b9c0 R15: 1ffff9200175fd8f
 find_get_entry mm/filemap.c:2062 [inline]
 filemap_get_folios_tag+0x1e6/0x630 mm/filemap.c:2332
 mpage_map_and_submit_buffers fs/ext4/inode.c:2313 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2520 [inline]
 ext4_do_writepages+0x1afb/0x4500 fs/ext4/inode.c:2932
 ext4_writepages+0x203/0x350 fs/ext4/inode.c:3026
 do_writepages+0x32e/0x550 mm/page-writeback.c:2554
 __writeback_single_inode+0x133/0x1070 fs/fs-writeback.c:1750
 writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2041
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2118
 wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2229
 wb_check_old_data_flush fs/fs-writeback.c:2333 [inline]
 wb_do_writeback fs/fs-writeback.c:2386 [inline]
 wb_workfn+0xad2/0xed0 fs/fs-writeback.c:2414
 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+0x389/0x480 kernel/kthread.c:467
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: rcu_preempt kthread starved for 10537 jiffies! g9781 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:28080 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5282 [inline]
 __schedule+0x14ed/0x5040 kernel/sched/core.c:6894
 __schedule_loop kernel/sched/core.c:6976 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6991
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297
 kthread+0x389/0x480 kernel/kthread.c:467
 ret_from_fork+0x510/0xa50 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 43 2e 21 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c2
RAX: 00000000000a05b3 RBX: ffffffff8197561e RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8dab3e14 RDI: ffffffff8be259e0
RBP: ffffc90000197f10 R08: ffff8880b873375b R09: 1ffff110170e66eb
R10: dffffc0000000000 R11: ffffed10170e66ec R12: ffffffff8fc3fd70
R13: 1ffff11003b51b58 R14: 0000000000000001 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888125abb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555645c4ca0 CR3: 0000000072b98000 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+0x1be/0x4d0 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>