rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4555/1:b..l
(detected by 0, t=10502 jiffies, g=8257, q=460 ncpus=2)
task:syz.3.34 state:R running task stack:26496 pid:4555 ppid:4269 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90004caf640 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: d84065cab919b900
RDX: 0000000000000000 RSI: ffffffff8a8c1700 RDI: ffffffff8adef760
RBP: ffffc90004caf750 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000001
R13: 1ffff92000995ed4 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline]
percpu_ref_put+0x35/0x180 include/linux/percpu-refcount.h:351
css_put include/linux/cgroup.h:407 [inline]
__mem_cgroup_charge+0x52/0x80 mm/memcontrol.c:6945
mem_cgroup_charge include/linux/memcontrol.h:672 [inline]
shmem_add_to_page_cache+0x8fc/0x1c00 mm/shmem.c:708
shmem_get_folio_gfp+0x158b/0x3400 mm/shmem.c:1971
shmem_get_folio mm/shmem.c:2072 [inline]
shmem_write_begin+0xee/0x3f0 mm/shmem.c:2556
generic_perform_write+0x2db/0x560 mm/filemap.c:3846
__generic_file_write_iter+0x172/0x430 mm/filemap.c:3974
generic_file_write_iter+0xab/0x2e0 mm/filemap.c:4006
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x44c/0x960 fs/read_write.c:584
ksys_write+0x143/0x240 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd8b8b8da7f
RSP: 002b:00007fd8b998adf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fd8b8b8da7f
RDX: 0000000001000000 RSI: 00007fd8ae9f7000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000062ee
R10: 00002000000006c2 R11: 0000000000000293 R12: 0000000000000003
R13: 00007fd8b998aef0 R14: 00007fd8b998aeb0 R15: 00007fd8ae9f7000
rcu: rcu_preempt kthread starved for 10539 jiffies! g8257 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:28192 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 4541 Comm: syz.0.31 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 8f 41 f7 48 89 df e8 e6 54 42 f7 e8 31 48 65 f7 fb bf 01 00 00 00 76 cd 35 f7 65 8b 05 f7 84 e0 75 85 c0 74 02 5b c3 e8 44 96 de
RSP: 0018:ffffc90004c6fb98 EFLAGS: 00000282
RAX: 8067e4d049814700 RBX: ffff8880544f65c0 RCX: 8067e4d049814700
RDX: dffffc0000000000 RSI: ffffffff8a8c0580 RDI: 0000000000000001
RBP: ffff8880544f6a58 R08: dffffc0000000000 R09: ffffed100a89ecb9
R10: ffffed100a89ecb9 R11: 1ffff1100a89ecb8 R12: 1ffff1100a89ed4b
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
FS: 0000555561c51500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f903ff8 CR3: 0000000026b25000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1163/0x1350 kernel/signal.c:2874
arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f87c1a6f130
Code: 01 00 48 83 c0 01 48 39 f0 72 ef e9 cb fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 48 c7 43 50 04 00 00 00 e9 06 fe ff ff 0f 1f 00 <48> 8b 0d 41 2f 37 00 48 81 ce ff ff ff 3f 31 c0 48 3b 34 c1 74 5b
RSP: 002b:00007ffe352a5db0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 00007f87c2915720 RCX: ffffffff83cf1f25
RDX: 0000000000001f25 RSI: ffffffff83cf1f25 RDI: 0000000000000016
RBP: ffffffff83cf1f25 R08: 00007f87c1de6128 R09: 00007f87c1dd2000
R10: 00007f87c11fd008 R11: 0000000000000016 R12: 0000000000000016
R13: 0000000000000000 R14: ffffffff83cf1dac R15: 00000000000024ef