GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (2 ticks this GP) idle=988c/1/0x4000000000000000 softirq=30517/30517 fqs=1
rcu: (detected by 1, t=10504 jiffies, g=28873, q=108 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8835 Comm: syz.2.756 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:iterate_chain_key kernel/locking/lockdep.c:451 [inline]
RIP: 0010:__lock_acquire+0x555/0x2630 kernel/locking/lockdep.c:5225
Code: ff 1f c1 e0 0d 44 09 c8 98 44 29 c0 31 f8 89 f7 89 c6 29 c7 01 d0 c1 c6 06 31 fe 89 f7 29 f2 01 c6 c1 c7 08 31 d7 89 fa 29 f8 <01> f7 c1 c2 10 41 89 f8 31 c2 89 d0 29 d6 01 fa c1 c8 0d 31 c6 89
RSP: 0018:ffffc90000007c80 EFLAGS: 00000012
RAX: 000000000329e73d RBX: ffff8880684cd5b8 RCX: 0000000000000001
RDX: 00000000fcd60c27 RSI: 00000000fffcc88a RDI: 00000000fcd60c27
RBP: ffff8880684cca00 R08: 00000000ffffffff R09: 0000000000000c98
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000c98 R14: 0000000000000000 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff888124379000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200001000000 CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825
__raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
spin_lock include/linux/spinlock.h:342 [inline]
advance_sched+0xe5/0xd20 net/sched/sch_taprio.c:930
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x167b/0x2090 arch/x86/kernel/unwind_orc.c:694
Code: 00 0f 84 42 f9 ff ff 4c 89 e7 e8 20 71 be 00 e9 35 f9 ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 48 c1 ea 03 80 3c 02 00 <0f> 85 29 06 00 00 49 8d 7d 08 49 8b 5d 38 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc900030a6ef0 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff917b52ca
RDX: 1ffff92000614df3 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc900030a6fa8 R08: ffffffff917b52ce R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000f2da R12: ffffc900030a6fb0
R13: ffffc900030a6f60 R14: ffffc900030a7090 R15: ffffc900030a6f94
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
free_unref_folios+0xa0d/0x16f0 mm/page_alloc.c:3004
folios_put_refs+0x571/0xa90 mm/swap.c:1008
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x3f3/0xc40 mm/shmem.c:1407
evict+0x3c2/0xad0 fs/inode.c:841
iput_final fs/inode.c:1960 [inline]
iput.part.0+0x605/0xf50 fs/inode.c:2009
iput+0x35/0x40 fs/inode.c:1975
dentry_unlink_inode+0x2c0/0x4c0 fs/dcache.c:476
__dentry_kill+0x1d0/0x690 fs/dcache.c:718
finish_dput+0x76/0x480 fs/dcache.c:927
dput.part.0+0x456/0x570 fs/dcache.c:976
dput+0x1f/0x30 fs/dcache.c:968
__fput+0x519/0xb50 fs/file_table.c:518
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d2/0x2a60 kernel/exit.c:975
do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
get_signal+0x1ec7/0x21e0 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b4819cdd9
Code: Unable to access opcode bytes at 0x7f7b4819cdaf.
RSP: 002b:00007f7b49060028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 000000000003ffff RBX: 00007f7b48416090 RCX: 00007f7b4819cdd9
RDX: 00000000080002c1 RSI: 0000200000000040 RDI: 0000000000000003
RBP: 00007f7b48232d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b48416128 R14: 00007f7b48416090 R15: 00007ffdb5038648
rcu: rcu_preempt kthread starved for 10502 jiffies! g28873 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:27992 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7282
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+0x72b/0xd50 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: 8846 Comm: syz.4.761 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x1700 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 89 7c 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45 08 31
RSP: 0018:ffffc90003e17a80 EFLAGS: 00000246
RAX: 0000000000080000 RBX: 0000000000000000 RCX: ffffc90006203000
RDX: 0000000000080000 RSI: ffffffff81fc0f17 RDI: ffff8880684c8000
RBP: ffff8880b8443320 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed1017088665 R14: 0000000000000001 R15: ffff8880b853c5c0
FS: 00007f35825f66c0(0000) GS:ffff888124479000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33318ff8 CR3: 000000006ab21000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x37a/0x550 kernel/jump_label.c:910
static_key_enable_cpuslocked+0x1bc/0x270 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
__sched_core_enable kernel/sched/core.c:475 [inline]
sched_core_get+0x8a/0xa0 kernel/sched/core.c:499
sched_core_alloc_cookie kernel/sched/core_sched.c:20 [inline]
sched_core_share_pid+0x406/0x9d0 kernel/sched/core_sched.c:187
__do_sys_prctl+0x6bd/0x2310 kernel/sys.c:2808
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f358439cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f35825f6028 EFLAGS: 00000246 ORIG_RAX: 000000000000009d
RAX: ffffffffffffffda RBX: 00007f3584615fa0 RCX: 00007f358439cdd9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000003e
RBP: 00007f3584432d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3584616038 R14: 00007f3584615fa0 R15: 00007ffd526a1d08