rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P1104/2:b..l P12/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=9317, q=854 ncpus=2)
task:kworker/u8:0    state:R  running task     stack:25496 pid:12    tgid:12    ppid:2      task_flags:0x4248060 flags:0x00080000
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319
Code: 00 00 00 eb b6 e8 80 fa ff ff eb b6 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 8b 05 36 be 21 05 85 c0 74 20 8b 05 c0 ed 21 05 85 c0
RSP: 0018:ffffc900001170b8 EFLAGS: 00000283
RAX: ffffc90000118001 RBX: ffffc900001174c0 RCX: ffffc90000118001
RDX: ffffc900001174c8 RSI: ffffc900001174a8 RDI: ffffc90000117140
RBP: 0000000000000001 R08: 0000000000000001 R09: 00000000c9b046df
R10: ffff88801d6854b0 R11: 00000000000126dd R12: ffffc90000117180
R13: ffffc90000117130 R14: ffffc900001174c0 R15: ffffc90000117164
 rcu_read_unlock include/linux/rcupdate.h:895 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0x3de/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
 kasan_save_free_info mm/kasan/kasan.h:406 [inline]
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6663 [inline]
 kfree+0x2f8/0x6e0 mm/slub.c:6871
 ext4_free_ext_path+0xe4/0x120 fs/ext4/extents.c:129
 ext4_ext_map_blocks+0x737/0x5f10 fs/ext4/extents.c:4454
 ext4_map_create_blocks fs/ext4/inode.c:613 [inline]
 ext4_map_blocks+0x573/0x1350 fs/ext4/inode.c:816
 ext4_convert_unwritten_extents+0x2ad/0x4c0 fs/ext4/extents.c:4976
 ext4_convert_unwritten_io_end_vec+0x127/0x280 fs/ext4/extents.c:5016
 ext4_end_io_end+0xd5/0x4a0 fs/ext4/page-io.c:199
 ext4_do_flush_completed_IO fs/ext4/page-io.c:290 [inline]
 ext4_end_io_rsv_work+0x205/0x380 fs/ext4/page-io.c:305
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
task:kworker/u8:7    state:R  running task     stack:23080 pid:1104  tgid:1104  ppid:2      task_flags:0x24248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2429 [inline]
RIP: 0010:raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline]
RIP: 0010:atomic_add_unless include/linux/atomic/atomic-instrumented.h:1518 [inline]
RIP: 0010:page_ref_add_unless.constprop.0+0x9c/0x390 include/linux/page_ref.h:238
Code: 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 c5 02 00 00 8b 5b 34 <e8> 6f 70 c7 ff 31 ff 89 de 41 89 dd e8 13 6b c7 ff 85 db 0f 84 9f
RSP: 0018:ffffc90003f3edc0 EFLAGS: 00000246
RAX: 0000000000000007 RBX: 0000000000000003 RCX: ffffffff81f6959f
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea00019577b4
RBP: ffffea00019577b4 R08: 0000000000000001 R09: fffff9400032aef6
R10: ffffea00019577b7 R11: 000000002128a245 R12: 0000000000000000
R13: 0000000000000013 R14: ffffc90003f3efe8 R15: dffffc0000000000
 folio_ref_add_unless include/linux/page_ref.h:248 [inline]
 folio_try_get include/linux/page_ref.h:264 [inline]
 find_get_entry mm/filemap.c:2069 [inline]
 filemap_get_folios_tag+0x1d5/0xae0 mm/filemap.c:2325
 mpage_map_and_submit_buffers+0x27a/0xb40 fs/ext4/inode.c:2313
 mpage_map_and_submit_extent fs/ext4/inode.c:2520 [inline]
 ext4_do_writepages+0x20f5/0x3c70 fs/ext4/inode.c:2932
 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3026
 do_writepages+0x27a/0x600 mm/page-writeback.c:2598
 __writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737
 writeback_sb_inodes+0x795/0x1de0 fs/fs-writeback.c:2030
 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2107
 wb_writeback+0x799/0xae0 fs/fs-writeback.c:2218
 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
 wb_do_writeback fs/fs-writeback.c:2375 [inline]
 wb_workfn+0x8a0/0xbb0 fs/fs-writeback.c:2403
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 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 10588 jiffies! g9317 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:29112 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 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:
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:__rhashtable_lookup include/linux/rhashtable.h:626 [inline]
RIP: 0010:rhltable_lookup include/linux/rhashtable.h:731 [inline]
RIP: 0010:link_sta_info_hash_lookup+0x4c/0x690 net/mac80211/sta_info.c:253
Code: 0a 00 00 48 89 c2 48 89 44 24 28 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 0d 06 00 00 48 8b ab a0 0a 00 00 <e8> 7f 7f 91 00 31 ff 41 89 c4 89 c6 e8 e3 58 ea f6 45 85 e4 0f 85
RSP: 0018:ffffc90000a08af0 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff888031b98e80 RCX: ffffffff8ad3b600
RDX: 1ffff11006373324 RSI: ffffffff8ad3a7ce RDI: ffff888031b98e80
RBP: ffff88814cb8d600 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 000000000ac0d5af R12: ffff888031b98e80
R13: ffff888055b04d80 R14: 0000000000000001 R15: ffff888055b05ad0
FS:  0000000000000000(0000) GS:ffff888124a68000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000020000 CR3: 000000005cccc000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 link_sta_info_get_bss+0x9a/0x460 net/mac80211/sta_info.c:265
 ieee80211_rx_for_interface+0x74/0x770 net/mac80211/rx.c:5197
 __ieee80211_rx_handle_packet net/mac80211/rx.c:5400 [inline]
 ieee80211_rx_list+0x1141/0x2ed0 net/mac80211/rx.c:5539
 ieee80211_rx_napi+0xdc/0x410 net/mac80211/rx.c:5562
 ieee80211_rx include/net/mac80211.h:5216 [inline]
 ieee80211_handle_queued_frames+0xcf/0x130 net/mac80211/main.c:452
 tasklet_action_common+0x254/0x3f0 kernel/softirq.c:925
 handle_softirqs+0x219/0x8b0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 66 71 02 e9 93 2f 03 00 0f 1f 00 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 13 23 25 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c2
RAX: 000000000036f769 RBX: 0000000000000001 RCX: ffffffff8b6536f9
RDX: 0000000000000000 RSI: ffffffff8dabb765 RDI: ffffffff8bf21180
RBP: ffffed1003b55498 R08: 0000000000000001 R09: ffffed10170a671d
R10: ffff8880b85338eb R11: 00000000ffffffff R12: 0000000000000001
R13: ffff88801daaa4c0 R14: ffffffff9086e4d0 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x38d/0x510 kernel/sched/idle.c:332
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>