rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13725/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=59893, q=820 ncpus=2)
task:syz.2.1961 state:R running task stack:25128 pid:13725 tgid:13719 ppid:5819 task_flags:0x20400040 flags:0x00080002
Call Trace:
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:lock_release+0x183/0x2d0 kernel/locking/lockdep.c:5893
Code: 0f c1 05 58 c3 17 12 83 f8 01 0f 85 03 01 00 00 9c 58 f6 c4 02 0f 85 ee 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 ed 7b 17 12 0f 85 32 01 00 00 48 83 c4 18 5b 41 5c 41
RSP: 0018:ffffc900034470f0 EFLAGS: 00000206
RAX: 4fab9627ebe9b400 RBX: ffffffff8e3c9620 RCX: ffffc900034470fc
RDX: 0000000000000000 RSI: ffffffff8da9bf6a RDI: ffffffff8bf24280
RBP: 0000000000000001 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000002 R11: 0000000000006cdb R12: ffffffff816cb9a4
R13: 0000000000000206 R14: ffff8880335424c0 R15: 0000000000000001
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
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
unpoison_slab_object mm/kasan/common.c:339 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4948 [inline]
slab_alloc_node mm/slub.c:5258 [inline]
kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5265
mempool_alloc_noprof+0x1b4/0x2f0 mm/mempool.c:567
bio_alloc_bioset+0x47e/0x8d0 block/bio.c:559
bio_alloc include/linux/bio.h:374 [inline]
submit_bh_wbc+0x280/0x740 fs/buffer.c:2804
__block_write_full_folio+0x735/0xe00 fs/buffer.c:1933
block_write_full_folio+0x31d/0x3e0 fs/buffer.c:2753
blkdev_writepages+0xb8/0x140 block/fops.c:491
do_writepages+0x27a/0x600 mm/page-writeback.c:2598
filemap_writeback+0x225/0x2d0 mm/filemap.c:387
filemap_fdatawrite_range mm/filemap.c:412 [inline]
filemap_write_and_wait_range.part.0+0x88/0x110 mm/filemap.c:684
filemap_write_and_wait_range mm/filemap.c:680 [inline]
filemap_invalidate_pages mm/filemap.c:2904 [inline]
kiocb_invalidate_pages+0xde/0x180 mm/filemap.c:2923
blkdev_direct_write block/fops.c:720 [inline]
blkdev_write_iter+0x48f/0xe00 block/fops.c:795
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x12a/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faec278f749
RSP: 002b:00007faec365f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007faec29e6090 RCX: 00007faec278f749
RDX: 00000000ffffffdb RSI: 0000000000000000 RDI: 000000000000000e
RBP: 00007faec2813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faec29e6128 R14: 00007faec29e6090 R15: 00007ffd4eaf9058
rcu: rcu_preempt kthread starved for 10553 jiffies! g59893 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:28320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 06 60 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 13 59 13 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 000000000485dcc9 RBX: 0000000000000000 RCX: ffffffff8b7706d9
RDX: 0000000000000000 RSI: ffffffff8dac200a RDI: ffffffff8bf24280
RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d
R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000
R13: ffffffff8e097b40 R14: ffffffff9087f7d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124909000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbb997e20c0 CR3: 000000000e184000 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:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3ef/0x4d0 init/main.c:1206
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148