rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=ded4/1/0x4000000000000000 softirq=18340/18341 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6503/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=13525, q=865 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6526 Comm: syz.0.234 Not tainted 6.16.0-syzkaller-12063-g37816488247d #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_preemption_disabled+0x49/0x120 lib/smp_processor_id.c:53
Code: 8b 0d bb 1e 27 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 9b 1e 27 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f <5d> e9 41 ca 02 00 cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24
RSP: 0018:ffffc90000007b30 EFLAGS: 00000086
RAX: 0000000000000000 RBX: 0000000000000000 RCX: bf77a20ae8f44e00
RDX: 0000000000000000 RSI: ffffffff8dba3961 RDI: ffffffff8be32680
RBP: ffffffff84cf75ab R08: 0000000000000000 R09: ffffffff84cf75ab
R10: ffffc90000007ca0 R11: fffff52000000f96 R12: 0000000000000000
R13: ffffffff99d8e538 R14: 0000000000000001 R15: 0000000000000046
FS: 000055556e04c500(0000) GS:ffff888125c21000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556e04c808 CR3: 0000000076a4a000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lock_acquire+0x130/0x360 kernel/locking/lockdep.c:5870
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
debug_object_activate+0xbb/0x420 lib/debugobjects.c:818
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:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:put_cpu_partial+0x1b4/0x250 mm/slub.c:3292
Code: 85 b5 00 00 00 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 d8 f6 5f 09 f7 c5 00 02 00 00 74 bc fb 4d 85 e4 <75> bb eb c4 90 e8 a2 28 ab 02 85 c0 74 22 83 3d 0b b7 8a 0d 00 75
RSP: 0018:ffffc9000ee778a8 EFLAGS: 00000282
RAX: bf77a20ae8f44e00 RBX: ffff88801a441280 RCX: bf77a20ae8f44e00
RDX: 0000000000000007 RSI: ffffffff8d9b4943 RDI: ffffffff8be32680
RBP: 0000000000000282 R08: ffffffff8fa34737 R09: 1ffffffff1f468e6
R10: dffffc0000000000 R11: fffffbfff1f468e7 R12: ffffea0001d60c40
R13: 0000000000000000 R14: ffff888026aa0000 R15: ffff8880b863e390
__slab_free+0x2d5/0x3c0 mm/slub.c:4550
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4180 [inline]
slab_alloc_node mm/slub.c:4229 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236
taskstats_tgid_alloc kernel/taskstats.c:576 [inline]
taskstats_exit+0x14a/0xa30 kernel/taskstats.c:615
do_exit+0x630/0x2300 kernel/exit.c:936
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faa16f8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe3e56eff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffdfc RBX: 0000000000022e35 RCX: 00007faa16f8ebe9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007faa171b5fac
RBP: 0000000000000226 R08: 7fffffffffffffff R09: 000000023e56f2ef
R10: 00007ffe3e56f0f0 R11: 0000000000000246 R12: 00007faa171b5fac
R13: 00007ffe3e56f0f0 R14: 000000000002305b R15: 00007ffe3e56f110
task:syz.4.225 state:R running task stack:24984 pid:6503 tgid:6502 ppid:5870 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7238
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5879
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__set_page_owner+0x8d/0x4a0 mm/page_owner.c:329
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
prep_new_page mm/page_alloc.c:1859 [inline]
get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
__alloc_pages_noprof mm/page_alloc.c:5182 [inline]
alloc_pages_bulk_noprof+0x560/0x710 mm/page_alloc.c:5102
___alloc_pages_bulk mm/kasan/shadow.c:344 [inline]
__kasan_populate_vmalloc mm/kasan/shadow.c:368 [inline]
kasan_populate_vmalloc+0xba/0x1a0 mm/kasan/shadow.c:417
alloc_vmap_area+0xd51/0x1490 mm/vmalloc.c:2092
__get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3187
get_vm_area+0x80/0xb0 mm/vmalloc.c:3229
arena_map_alloc+0x256/0x520 kernel/bpf/arena.c:125
map_create+0xaa0/0x14d0 kernel/bpf/syscall.c:1480
__sys_bpf+0x60f/0x870 kernel/bpf/syscall.c:6011
__do_sys_bpf kernel/bpf/syscall.c:6139 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6137 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6137
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f733938ebe9
RSP: 002b:00007f733a272038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f73395b5fa0 RCX: 00007f733938ebe9
RDX: 0000000000000050 RSI: 0000200000000480 RDI: 0000000000000000
RBP: 00007f7339411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f73395b6038 R14: 00007f73395b5fa0 R15: 00007ffeb5a3ccb8
rcu: rcu_preempt kthread starved for 10502 jiffies! g13525 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 12 Comm: kworker/u8:0 Not tainted 6.16.0-syzkaller-12063-g37816488247d #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217
Code: 08 f0 9f 92 65 8b 15 68 44 e0 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 <83> fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c
RSP: 0018:ffffc90000116398 EFLAGS: 00000246
RAX: ffffffff81b44d6b RBX: 1ffff110170c8341 RCX: ffff88801ce95a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000116520 R08: ffff8880315e2a47 R09: 1ffff110062bc548
R10: dffffc0000000000 R11: ffffffff8174ae50 R12: ffff8880b8641a08
R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125d21000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e33f76e490 CR3: 0000000077c98000 CR4: 00000000003526f0
Call Trace:
csd_lock_wait kernel/smp.c:342 [inline]
smp_call_function_many_cond+0xd4b/0x12d0 kernel/smp.c:877
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451
flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:101
page_vma_mkclean_one+0x406/0x740 mm/rmap.c:1059
page_mkclean_one+0x1c0/0x280 mm/rmap.c:1100
__rmap_walk_file+0x467/0x620 mm/rmap.c:2905
rmap_walk mm/rmap.c:2949 [inline]
folio_mkclean+0x297/0x390 mm/rmap.c:1132
folio_clear_dirty_for_io+0x1fa/0x8c0 mm/page-writeback.c:2962
mpage_submit_folio+0x86/0x2b0 fs/ext4/inode.c:2061
mpage_map_and_submit_buffers fs/ext4/inode.c:2324 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2514 [inline]
ext4_do_writepages+0x1d43/0x4610 fs/ext4/inode.c:2931
ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025
do_writepages+0x32e/0x550 mm/page-writeback.c:2634
__writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680
writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245