rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14543/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=72833, q=1914 ncpus=2)
task:syz.3.1810 state:R running task stack:27848 pid:14543 tgid:14538 ppid:5831 task_flags:0x20400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6908
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235
irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5872
Code: 05 7b d2 28 12 83 f8 07 0f 87 f0 00 00 00 48 0f a3 05 46 4f f5 0e 0f 82 c2 02 00 00 8b 35 0e 83 f5 0e 85 f6 0f 85 dd 00 00 00 <48> 8b 44 24 30 65 48 2b 05 1d d2 28 12 0f 85 02 03 00 00 48 83 c4
RSP: 0018:ffffc90009597308 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8de57649 RDI: ffffffff8c1af920
RBP: ffffffff8e7e7420 R08: 0000000086db7919 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4542 [inline]
slab_alloc_node mm/slub.c:4869 [inline]
kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4876
mempool_alloc_noprof+0x1b7/0x310 mm/mempool.c:566
bio_alloc_bioset+0x392/0x850 block/bio.c:598
bio_alloc include/linux/bio.h:368 [inline]
submit_bh_wbc+0x250/0x770 fs/buffer.c:2801
__block_write_full_folio+0x77f/0xee0 fs/buffer.c:1930
block_write_full_folio+0x3b5/0x4e0 fs/buffer.c:2750
blkdev_writepages+0xc7/0x150 block/fops.c:486
do_writepages+0x278/0x600 mm/page-writeback.c:2554
filemap_writeback+0x22d/0x2e0 mm/filemap.c:387
filemap_fdatawrite_range mm/filemap.c:412 [inline]
file_write_and_wait_range+0xcd/0x140 mm/filemap.c:786
blkdev_fsync+0x6c/0xd0 block/fops.c:619
vfs_fsync_range fs/sync.c:186 [inline]
vfs_fsync fs/sync.c:200 [inline]
do_fsync+0xbf/0x220 fs/sync.c:211
__do_sys_fdatasync fs/sync.c:221 [inline]
__se_sys_fdatasync fs/sync.c:219 [inline]
__x64_sys_fdatasync+0x35/0x50 fs/sync.c:219
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a4599c799
RSP: 002b:00007f5a468ad028 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: ffffffffffffffda RBX: 00007f5a45c16090 RCX: 00007f5a4599c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f5a45a32bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5a45c16128 R14: 00007f5a45c16090 R15: 00007fff2f0fb268
rcu: rcu_preempt kthread starved for 10184 jiffies! g72833 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:27832 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7005
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: d8 85 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 a3 8f 1e 00 fb f4 fc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000246
RAX: 000000000044b4e1 RBX: ffff88801e6a0000 RCX: ffffffff8b8cfc75
RDX: 0000000000000000 RSI: ffffffff8de7d6cc RDI: ffffffff8c1af920
RBP: 0000000000000001 R08: 0000000000000001 R09: ffffed10170a6795
R10: ffff8880b8533cab R11: 0000000000000000 R12: ffffed1003cd4000
R13: 0000000000000001 R14: ffffffff90d9ad10 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812444d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000600000 CR3: 000000007bb14000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
default_idle+0x9/0x10 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+0x35b/0x4b0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148