GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=c1cc/1/0x4000000000000000 softirq=67077/67082 fqs=2
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9497/1:b..l
rcu: (detected by 1, t=10506 jiffies, g=49577, q=404 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13378 Comm: syz.6.2264 Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:find_held_lock kernel/locking/lockdep.c:-1 [inline]
RIP: 0010:__lock_release kernel/locking/lockdep.c:5533 [inline]
RIP: 0010:lock_release+0x12c/0x3e0 kernel/locking/lockdep.c:5887
Code: 24 83 f8 32 0f 83 44 02 00 00 4a 8d 1c ad 00 00 00 00 4c 01 eb 48 8d 6c dd 00 48 89 ef 4c 89 f6 e8 e9 fd b7 09 44 89 64 24 14 <45> 89 e5 85 c0 0f 84 dd 00 00 00 48 85 ed 0f 84 19 01 00 00 83 7d
RSP: 0018:ffffc90000007b78 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000014 RCX: 0bda8b8d89cd6000
RDX: 0000000000000001 RSI: ffffffff999f6e88 RDI: ffff88802b928b90
RBP: ffff88802b928b90 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f6c R12: 0000000000000004
R13: 0000000000000004 R14: ffffffff999f6e88 R15: ffff88802b928000
FS: 0000000000000000(0000) GS:ffff8881260cb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30b1dff8 CR3: 000000000dd36000 CR4: 0000000000350ef0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
_raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194
debug_object_activate+0x2e2/0x420 lib/debugobjects.c:836
debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline]
debug_activate kernel/time/hrtimer.c:484 [inline]
enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088
__run_hrtimer kernel/time/hrtimer.c:1778 [inline]
__hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x8/0x90 kernel/kcov.c:300
Code: 20 e9 d7 6d 50 ff cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 14 25 08 50 75 92 65 8b 0d c8 7c b5 10 81 e1 00 01 ff 00
RSP: 0018:ffffc9000da37388 EFLAGS: 00000246
RAX: ffffffff821030af RBX: ffffea000189a700 RCX: 0000000000000000
RDX: ffff88802b928000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffea000189a733 R09: 1ffffd40003134e6
R10: dffffc0000000000 R11: fffff940003134e7 R12: ffffea000189a700
R13: ffff8880668a5dc0 R14: 0000000000000001 R15: dffffc0000000000
__folio_mod_stat mm/rmap.c:1410 [inline]
__folio_remove_rmap mm/rmap.c:1777 [inline]
folio_remove_rmap_ptes+0xef/0xaf0 mm/rmap.c:1804
zap_present_folio_ptes mm/memory.c:1525 [inline]
zap_present_ptes mm/memory.c:1586 [inline]
do_zap_pte_range mm/memory.c:1687 [inline]
zap_pte_range mm/memory.c:1731 [inline]
zap_pmd_range mm/memory.c:1823 [inline]
zap_pud_range mm/memory.c:1852 [inline]
zap_p4d_range mm/memory.c:1873 [inline]
unmap_page_range+0x17f2/0x4210 mm/memory.c:1894
unmap_vmas+0x25d/0x3c0 mm/memory.c:1984
exit_mmap+0x245/0xba0 mm/mmap.c:1284
__mmput+0x118/0x420 kernel/fork.c:1379
exit_mm+0x1da/0x2c0 kernel/exit.c:589
do_exit+0x859/0x2550 kernel/exit.c:940
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x125e/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218
do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f226c38e969
Code: Unable to access opcode bytes at 0x7f226c38e93f.
RSP: 002b:00007f226d1a90e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f226c5b5fa8 RCX: 00007f226c38e969
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f226c5b5fac
RBP: 00007f226c5b5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f226c5b5fac
R13: 0000000000000000 R14: 00007ffea8e99c40 R15: 00007ffea8e99d28
task:syz-executor state:R running task stack:21272 pid:9497 tgid:9497 ppid:9482 task_flags:0x400140 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:842 [inline]
RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
RIP: 0010:unwind_next_frame+0xd6/0x2390 arch/x86/kernel/unwind_orc.c:479
Code: 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 41 57 e8 2e 73 2c 00 48 83 c4 08 e8 35 84 e4 09 85 c0 74 3a e8 5c 4d 35 00 84 c0 <75> 31 e8 23 84 e4 09 85 c0 74 28 80 3d bc 04 f7 0d 00 75 1f c6 05
RSP: 0018:ffffc90004ad7178 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff822aeed7 RCX: c189069e3705b700
RDX: 0000000000000001 RSI: ffffffff8bc1d200 RDI: ffffffff8bc1d1c0
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8171a9f5 R12: 1ffff9200095ae49
R13: ffffc90004ad7280 R14: ffffc90004ad7248 R15: ffffffff8171a9f5
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1262 [inline]
free_unref_folios+0xb81/0x14a0 mm/page_alloc.c:2782
folios_put_refs+0x559/0x640 mm/swap.c:992
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1125
shmem_truncate_range mm/shmem.c:1237 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1365
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:660
dput+0x19f/0x2b0 fs/dcache.c:902
__fput+0x68e/0xa70 fs/file_table.c:473
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218
do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff27ff8d5ca
RSP: 002b:00007fffb74917c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007ff27ff8d5ca
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fffb749181c R08: 0000000000000000 R09: 00007fffb7491527
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000000be
R13: 00000000000927c0 R14: 0000000000079485 R15: 00007fffb7491870
rcu: rcu_preempt kthread starved for 10495 jiffies! g49577 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153
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: 53 Comm: kworker/u8:3 Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d fc 13 d7 0b 48 89 de 5b e9 93 62 57 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 50 75 92 65 8b 15 c8 7f b5 10 81 e2 00 01 ff 00
RSP: 0018:ffffc90000bf76f8 EFLAGS: 00000202
RAX: ffffffff81b467a0 RBX: ffff8880b893ad40 RCX: ffff88801d6c3c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000bf7860 R08: ffffffff8f7ed977 R09: 1ffffffff1efdb2e
R10: dffffc0000000000 R11: fffffbfff1efdb2f R12: 1ffff11017108245
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8841228
FS: 0000000000000000(0000) GS:ffff8881261cb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002000 CR3: 000000000dd36000 CR4: 0000000000350ef0
Call Trace:
csd_lock_wait kernel/smp.c:340 [inline]
smp_call_function_many_cond+0xe80/0x11c0 kernel/smp.c:885
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2455 [inline]
text_poke_bp_batch+0x319/0x940 arch/x86/kernel/alternative.c:2665
text_poke_flush arch/x86/kernel/alternative.c:2856 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2863
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245