rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20062/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=96865, q=3515 ncpus=2)
task:syz.1.3080 state:R running task stack:25256 pid:20062 tgid:20057 ppid:17469 task_flags:0x20400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
irqentry_exit+0x36/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:phys_addr_valid arch/x86/mm/physaddr.h:7 [inline]
RIP: 0010:__phys_addr+0x9c/0x180 arch/x86/mm/physaddr.c:28
Code: 00 48 39 eb 72 7c e8 53 c4 4e 00 48 c7 c0 61 33 83 90 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 c1 e9 03 0f b6 14 11 <38> c2 7f 08 84 d2 0f 85 9c 00 00 00 0f b6 1d 22 3f 15 0f bf 3f 00
RSP: 0018:ffffc9000bb071e0 EFLAGS: 00000a06
RAX: 0000000000000001 RBX: ffff8880fef33780 RCX: 1ffffffff210666c
RDX: 0000000000000000 RSI: ffffffff816df40d RDI: 0000000000000006
RBP: 000000007ef33780 R08: 0000000000000006 R09: ffff8880fef33780
R10: 000000007ef33780 R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff9acbc13c R14: 0000000000000002 R15: ffff888020eaf000
virt_to_folio include/linux/mm.h:1245 [inline]
virt_to_slab mm/slab.h:191 [inline]
kmem_cache_free+0x7f/0x6c0 mm/slub.c:6729
mempool_free+0x102/0x750 mm/mempool.c:576
bio_put_percpu_cache block/bio.c:805 [inline]
bio_put+0x355/0x5b0 block/bio.c:824
bio_endio+0x713/0x860 block/bio.c:1672
blk_update_request+0x93e/0x15f0 block/blk-mq.c:998
blk_mq_end_request+0x4f/0x90 block/blk-mq.c:1160
blk_mq_complete_request block/blk-mq.c:1338 [inline]
blk_mq_complete_request+0x8b/0xb0 block/blk-mq.c:1335
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:2837 [inline]
__blk_mq_flush_list+0x9a/0xc0 block/blk-mq.c:2833
blk_mq_dispatch_queue_requests+0x184/0x7b0 block/blk-mq.c:2882
blk_mq_flush_plug_list+0x1f2/0x600 block/blk-mq.c:2970
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1225
blk_finish_plug block/blk-core.c:1252 [inline]
blk_finish_plug+0x53/0xa0 block/blk-core.c:1249
blkdev_writepages+0xe9/0x140 block/fops.c:492
do_writepages+0x27a/0x600 mm/page-writeback.c:2604
filemap_fdatawrite_wbc mm/filemap.c:389 [inline]
filemap_fdatawrite_wbc+0x104/0x160 mm/filemap.c:379
__filemap_fdatawrite_range+0xb9/0x100 mm/filemap.c:422
filemap_write_and_wait_range mm/filemap.c:694 [inline]
filemap_write_and_wait_range+0xa3/0x130 mm/filemap.c:685
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:709
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:227
get_signal+0x1d0/0x26d0 kernel/signal.c:2807
arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd23098efc9
RSP: 002b:00007fd2317c8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 0000000001000000 RBX: 00007fd230be6090 RCX: 00007fd23098efc9
RDX: 0000000080000000 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007fd230a11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd230be6128 R14: 00007fd230be6090 R15: 00007ffe0eb19398
rcu: rcu_preempt kthread starved for 5396 jiffies! g96865 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:28376 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
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+0x675/0x7d0 arch/x86/kernel/process.c:158
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 10/02/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 27 77 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 a3 26 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 0000000000730ab7 RBX: 0000000000000001 RCX: ffffffff8b6382a9
RDX: 0000000000000000 RSI: ffffffff8db0013c RDI: ffffffff8bf1e3c0
RBP: ffffed1003addb58 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000001 R12: 0000000000000001
R13: ffff88801d6edac0 R14: ffffffff908349d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124ae1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5486800218 CR3: 0000000077d8e000 CR4: 00000000003526f0
Call Trace:
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:190 [inline]
do_idle+0x38d/0x500 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