rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10180/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=37109, q=1803 ncpus=2)
task:syz.2.696 state:R running task stack:24872 pid:10180 tgid:10180 ppid:5869 task_flags:0x2040004c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_get_return_address+0x43/0xa0 arch/x86/kernel/unwind_orc.c:369
Code: fb 0f b6 04 02 84 c0 74 04 3c 03 7e 59 8b 03 85 c0 75 09 31 c0 5b 5d c3 cc cc cc cc 48 b8 00 00 00 00 00 fc ff df 48 8d 6b 48 <48> 89 ea 48 c1 ea 03 80 3c 02 00 75 36 48 8b 7b 48 e8 27 6d 19 00
RSP: 0018:ffffc90003e6e960 EFLAGS: 00000202
RAX: dffffc0000000000 RBX: ffffc90003e6e978 RCX: ffffc90003e6e8cc
RDX: 1ffff920007cdd2f RSI: ffffffff8de296cd RDI: ffffc90003e6e978
RBP: ffffc90003e6e9c0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000002 R11: 000000000003bbda R12: ffffffff81a676b0
R13: ffffc90003e6ea38 R14: 0000000000000000 R15: ffff88801df73c00
arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:356
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4247
kmem_alloc_batch+0x49/0x170 lib/debugobjects.c:371
fill_pool lib/debugobjects.c:403 [inline]
debug_objects_fill_pool lib/debugobjects.c:725 [inline]
debug_objects_fill_pool+0x23f/0x520 lib/debugobjects.c:697
debug_object_activate+0x10b/0x4c0 lib/debugobjects.c:814
debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
__call_rcu_common.constprop.0+0x35/0xa10 kernel/rcu/tree.c:3108
slab_free_hook mm/slub.c:2386 [inline]
slab_free mm/slub.c:4695 [inline]
kmem_cache_free+0x16d/0x4d0 mm/slub.c:4797
mempool_free+0x102/0x750 mm/mempool.c:576
bio_put_percpu_cache block/bio.c:801 [inline]
bio_put+0x355/0x5b0 block/bio.c:820
bio_endio+0x710/0x860 block/bio.c:1651
blk_update_request+0x93e/0x15f0 block/blk-mq.c:989
blk_mq_end_request+0x4f/0x90 block/blk-mq.c:1151
blk_mq_complete_request block/blk-mq.c:1329 [inline]
blk_mq_complete_request+0x8b/0xb0 block/blk-mq.c:1326
nullb_complete_cmd drivers/block/null_blk/main.c:1402 [inline]
null_handle_cmd drivers/block/null_blk/main.c:1454 [inline]
null_queue_rq+0xb69/0xfd0 drivers/block/null_blk/main.c:1693
null_queue_rqs+0xe9/0x2f0 drivers/block/null_blk/main.c:1707
__blk_mq_flush_list block/blk-mq.c:2828 [inline]
__blk_mq_flush_list+0x97/0xc0 block/blk-mq.c:2824
blk_mq_dispatch_queue_requests+0x184/0x7b0 block/blk-mq.c:2873
blk_mq_flush_plug_list+0x1f2/0x600 block/blk-mq.c:2961
blk_add_rq_to_plug+0x1ca/0x540 block/blk-mq.c:1390
blk_mq_submit_bio+0x1a6b/0x2a10 block/blk-mq.c:3212
__submit_bio+0x3cf/0x690 block/blk-core.c:635
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x660/0xd30 block/blk-core.c:751
submit_bio_noacct+0xc20/0x1ed0 block/blk-core.c:874
__block_write_full_folio+0x735/0xe00 fs/buffer.c:1933
block_write_full_folio+0x341/0x400 fs/buffer.c:2753
blkdev_writepages+0xb8/0x140 block/fops.c:483
do_writepages+0x277/0x600 mm/page-writeback.c:2634
filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
filemap_fdatawrite_wbc+0x104/0x160 mm/filemap.c:376
__filemap_fdatawrite_range+0xb9/0x100 mm/filemap.c:419
filemap_write_and_wait_range mm/filemap.c:691 [inline]
filemap_write_and_wait_range+0xa3/0x130 mm/filemap.c:682
filemap_write_and_wait include/linux/pagemap.h:68 [inline]
sync_blockdev block/bdev.c:260 [inline]
sync_blockdev block/bdev.c:256 [inline]
bdev_release+0x4d3/0x6d0 block/bdev.c:1126
blkdev_release+0x15/0x20 block/fops.c:699
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x14d/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x86f/0x2bf0 kernel/exit.c:961
__do_sys_exit kernel/exit.c:1069 [inline]
__se_sys_exit kernel/exit.c:1067 [inline]
__x64_sys_exit+0x42/0x50 kernel/exit.c:1067
x64_sys_call+0x14f5/0x1720 arch/x86/include/generated/asm/syscalls_64.h:61
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa326d8ebe9
RSP: 002b:00007fa327bd7fe8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007fa326fc6360 RCX: 00007fa326d8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa326e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa326fc63f8 R14: 00007fa326fc6360 R15: 00007ffce30efcb8
rcu: rcu_preempt kthread starved for 2602 jiffies! g37109 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 8c 64 02 c3 cc cc cc cc 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 e3 d1 18 00 fb f4 7c 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6
RAX: 00000000002285cf RBX: 0000000000000001 RCX: ffffffff8b913bf9
RDX: 0000000000000000 RSI: ffffffff8de4eb79 RDI: ffffffff8c163180
RBP: ffffed1003cddb40 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801e6eda00 R14: ffffffff90aba190 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881247bd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555752017d0 CR3: 00000000257a6000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x391/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x148