rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6493/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=19137, q=546 ncpus=2)
task:dhcpcd-run-hook state:R running task stack:26648 pid:6493 tgid:6493 ppid:6442 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 60 ec c8 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 7a 1a 28 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 97 0d 29
RSP: 0018:ffffc90003f9f1f8 EFLAGS: 00000282
RAX: b816e1e9c2df8600 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000009e2c8a18 RSI: ffffffff8dc9a78a RDI: ffffffff8be259e0
RBP: ffffffff81743d75 R08: ffffffff81743d75 R09: ffffffff8e33efa0
R10: ffffc90003f9f358 R11: ffffffff81acf2b0 R12: 0000000000000002
R13: ffffffff8e33efa0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
slab_free_hook mm/slub.c:2517 [inline]
slab_free mm/slub.c:6690 [inline]
kmem_cache_free+0x475/0x620 mm/slub.c:6801
exit_mmap+0x52c/0xb10 mm/mmap.c:1302
__mmput+0x118/0x430 kernel/fork.c:1173
exec_mmap+0x3b5/0x440 fs/exec.c:901
begin_new_exec+0x1353/0x2440 fs/exec.c:1156
load_elf_binary+0x998/0x2740 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x92e/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2dce285107
RSP: 002b:00007ffef97a2c88 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 000055e68a3391a8 RCX: 00007f2dce285107
RDX: 000055e68a334e28 RSI: 000055e68a3391a8 RDI: 000055e68a334eb0
RBP: 000055e68a334eb0 R08: 00007ffef97a5eb3 R09: 0000000000000210
R10: 0000000000000002 R11: 0000000000000246 R12: 000055e68a334e28
R13: 00007f2dce44ae8b R14: 000055e68a334e28 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10449 jiffies! g19137 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:28080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
__schedule_loop kernel/sched/core.c:6976 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6991
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 6497 Comm: vhost-6496 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:222 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:233 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:649 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1231 [inline]
RIP: 0010:trace_ma_read+0x5c/0x1c0 include/trace/events/maple_tree.h:46
Code: 07 77 5f e8 46 57 61 f6 41 89 de c1 eb 06 48 8d 3c dd 70 fd c3 8f be 08 00 00 00 e8 6e 2a c8 f6 31 f6 4c 0f a3 35 d4 59 64 04 <0f> 92 c3 40 0f 92 c6 bf 02 00 00 00 e8 13 5a 61 f6 84 db 74 10 e8
RSP: 0018:ffffc90003f3f350 EFLAGS: 00000247
RAX: ffffffff8b5fa301 RBX: 0000000000000000 RCX: ffffffff8b5fa392
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8fc3fd70
RBP: ffffc90003f3f4b0 R08: ffffffff8fc3fd77 R09: 1ffffffff1f87fae
R10: dffffc0000000000 R11: fffffbfff1f87faf R12: ffffc90003f3f3e0
R13: 1ffff920007e7e78 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f3c4af566c0(0000) GS:ffff8881259bb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 0000000072068000 CR4: 00000000003526f0
Call Trace:
mt_find+0x112/0x5e0 lib/maple_tree.c:6490
find_vma+0xe7/0x160 mm/mmap.c:906
gup_vma_lookup mm/gup.c:1275 [inline]
__get_user_pages+0x3ae/0x29f0 mm/gup.c:1396
__get_user_pages_locked mm/gup.c:1692 [inline]
__gup_longterm_locked+0xde4/0x1660 mm/gup.c:2476
gup_fast_fallback+0x1d26/0x2290 mm/gup.c:3209
set_bit_to_user drivers/vhost/vhost.c:2425 [inline]
log_write+0xc3/0x390 drivers/vhost/vhost.c:2451
vhost_update_used_flags+0x1ed/0x2b0 drivers/vhost/vhost.c:2582
vhost_enable_notify+0xb9/0x670 drivers/vhost/vhost.c:3227
vhost_vsock_handle_tx_kick+0x2cb/0xfe0 drivers/vhost/vsock.c:519
vhost_run_work_list+0x14e/0x1e0 drivers/vhost/vhost.c:454
vhost_task_fn+0x27c/0x430 kernel/vhost_task.c:49
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246