rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P132/1:b..l P8331/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=66649, q=28 ncpus=2)
task:syz-executor state:R running task stack:21640 pid:8331 tgid:8331 ppid:8306 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7148
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7172
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
copy_pte_range mm/memory.c:1329 [inline]
copy_pmd_range+0x7630/0x7f00 mm/memory.c:1389
copy_pud_range mm/memory.c:1426 [inline]
copy_p4d_range mm/memory.c:1450 [inline]
copy_page_range+0xc14/0x1270 mm/memory.c:1538
dup_mmap+0xf4c/0x1b10 mm/mmap.c:1834
dup_mm kernel/fork.c:1504 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1556
copy_process+0x1706/0x3c00 kernel/fork.c:2196
kernel_clone+0x21e/0x840 kernel/fork.c:2624
__do_sys_clone kernel/fork.c:2765 [inline]
__se_sys_clone kernel/fork.c:2749 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2749
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdf8bb85493
RSP: 002b:00007ffdcff178a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdf8bb85493
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000555588e077d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000009e7e2 R15: 00007ffdcff17a40
task:kworker/u8:5 state:R running task stack:20296 pid:132 tgid:132 ppid:2 task_flags:0x4208160 flags:0x00080000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x521/0x2390 arch/x86/kernel/unwind_orc.c:512
Code: 63 18 00 00 0f b7 1e c1 eb 0b 80 e3 01 48 8b 44 24 28 0f b6 04 28 84 c0 4c 8b 7c 24 70 0f 85 6d 18 00 00 48 8b 44 24 10 88 18 <0f> b7 1e 83 e3 0f 83 fb 05 0f 8f 85 00 00 00 83 fb 03 0f 8f 01 01
RSP: 0018:ffffc90002e57438 EFLAGS: 00000246
RAX: ffffc90002e5759d RBX: 0000000000000000 RCX: ffffffff8fd6fae0
RDX: ffffffff9052fe22 RSI: ffffffff9052fe26 RDI: ffffffff8c03aa00
RBP: dffffc0000000000 R08: 0000000000000005 R09: ffffffff8173bd25
R10: ffffc90002e575b8 R11: fffff520005caeb9 R12: ffffffff9052fe27
R13: ffffc90002e575b8 R14: ffffc90002e57568 R15: ffffc90002e575a0
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4945 [inline]
slab_alloc_node mm/slub.c:5244 [inline]
kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5251
skb_clone+0x212/0x3a0 net/core/skbuff.c:2050
batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:386 [inline]
batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline]
batadv_iv_send_outstanding_bat_ogm_packet+0x5b5/0x7e0 net/batman-adv/bat_iv_ogm.c:1697
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 10490 jiffies! g66649 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:27288 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
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+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 15823 Comm: syz.5.2622 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lock_acquire+0x11b/0x360 kernel/locking/lockdep.c:5868
Code: 4c 89 7c 24 08 41 f7 c7 00 02 00 00 41 0f 94 c1 4c 89 ef 89 de 8b 54 24 04 44 89 e1 45 89 f0 6a 00 6a 00 6a 00 55 ff 74 24 30 e0 02 00 00 48 83 c4 28 48 c7 c7 0a 24 d9 8d e8 d0 82 e7 09 b8
RSP: 0018:ffffc90000007b38 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff99f16960
RBP: ffffffff84d5285a R08: 0000000000000001 R09: 0000000000000001
R10: ffffc90000007cb0 R11: fffff52000000f98 R12: 0000000000000000
R13: ffffffff99f16960 R14: 0000000000000001 R15: 0000000000000046
FS: 0000000000000000(0000) GS:ffff8881259e7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33217ff8 CR3: 0000000062f84000 CR4: 00000000003526f0
Call Trace:
__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_deactivate+0x9a/0x250 lib/debugobjects.c:873
debug_hrtimer_deactivate kernel/time/hrtimer.c:443 [inline]
debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:483
__run_hrtimer kernel/time/hrtimer.c:1745 [inline]
__hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5228
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 e9 27 05 00 00 4c 8b 75 d0 4c 89 e7 e8 7f 45 f6 09 e8 4a 52 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 58 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9001a82de78 EFLAGS: 00000286
RAX: c4f6f70180caa500 RBX: 0000000000000000 RCX: c4f6f70180caa500
RDX: 0000000000000006 RSI: ffffffff8dba2d53 RDI: ffffffff8c03aa60
RBP: ffffc9001a82ded0 R08: ffffffff8fc39677 R09: 1ffffffff1f872ce
R10: dffffc0000000000 R11: fffffbfff1f872cf R12: ffff888025675ac0
R13: dffffc0000000000 R14: ffff88802ae95ac0 R15: ffff8880b863ab98
context_switch kernel/sched/core.c:5363 [inline]
__schedule+0x17a0/0x4cc0 kernel/sched/core.c:6964
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:sized_strscpy+0x52/0x250 lib/string.c:170
Code: 7f 0f 87 d9 01 00 00 49 89 fe 48 ba 00 00 00 00 00 fc ff df 49 83 fc 08 48 89 34 24 72 70 31 ed eb 12 49 83 c4 f8 4d 89 2c 2e <48> 83 c5 08 49 83 fc 07 76 5c 4c 8b 2c 2e 4c 89 e8 48 f7 d0 48 b9
RSP: 0018:ffffc9001a82e260 EFLAGS: 00000217
RAX: 1ffff11003aced31 RBX: fffffffffffffff9 RCX: fefefefefefefeff
RDX: dffffc0000000000 RSI: ffff8880256763c0 RDI: ffff88801d676988
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff822dd89a
R10: ffff8880256763c0 R11: ffffffff81ac5170 R12: 0000000000000003
R13: 36322e352e7a7973 R14: ffff88801d676988 R15: 0000000000000000
sized_strscpy include/linux/fortify-string.h:329 [inline]
__update_page_owner_handle+0x307/0x570 mm/page_owner.c:253
__set_page_owner+0x10b/0x4a0 mm/page_owner.c:330
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
prep_new_page mm/page_alloc.c:1858 [inline]
get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3869
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5159
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2435
shmem_alloc_folio mm/shmem.c:1884 [inline]
shmem_alloc_and_add_folio+0x4ba/0x10f0 mm/shmem.c:1923
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2546
shmem_get_folio mm/shmem.c:2652 [inline]
shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3303
generic_perform_write+0x2c5/0x900 mm/filemap.c:4209
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3478
__kernel_write_iter+0x428/0x910 fs/read_write.c:619
dump_emit_page fs/coredump.c:1298 [inline]
dump_user_range+0x8a0/0xc90 fs/coredump.c:1372
elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111
coredump_write+0x116c/0x1900 fs/coredump.c:1049
vfs_coredump+0x1db5/0x2a60 fs/coredump.c:1170
get_signal+0x1108/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
irqentry_exit_to_user_mode+0x7e/0x110 kernel/entry/common.c:73
exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fdf8ba4f987
Code: 88 15 72 5d eb 00 88 05 6f 5d eb 00 c3 50 48 8d 35 c9 24 1c 00 48 8d 3d cf 24 1c 00 31 c0 e8 20 f7 ff ff 53 89 fb 48 83 ec 10 <64> 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8
RSP: 002b:00007fdf8c9ad120 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fdf8bb8ec29
RDX: 00007fdf8c9ad140 RSI: 00007fdf8c9ad270 RDI: 000000000000000b
RBP: 00007fdf8bc11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fdf8bdd6218 R14: 00007fdf8bdd6180 R15: 00007ffdcff17628