rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8402/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=30789, q=1073 ncpus=2)
task:syz.7.462 state:R running task stack:23840 pid:8402 tgid:8398 ppid:7959 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:debug_lockdep_rcu_enabled+0xd/0x40 kernel/rcu/update.c:320
Code: 8d 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 17 78 44 04 00 <74> 1e 83 3d 2a a7 44 04 00 74 15 65 48 8b 0c 25 08 b0 9f 92 31 c0
RSP: 0018:ffffc90002f77170 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff90dc8c01 RCX: ffffc90002f77f50
RDX: ffffc90002f77201 RSI: dffffc0000000000 RDI: ffffc90002f77250
RBP: dffffc0000000000 R08: ffffc90002f77f38 R09: 0000000000000000
R10: ffffc90002f77298 R11: fffff520005eee55 R12: ffffc90002f77f48
R13: ffffc90002f70000 R14: ffffc90002f77248 R15: ffffffff81742f85
rcu_read_unlock include/linux/rcupdate.h:895 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x1a64/0x23d0 arch/x86/kernel/unwind_orc.c:695
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5267 [inline]
kmem_cache_alloc_lru_noprof+0x36c/0x6e0 mm/slub.c:5286
sock_alloc_inode+0x28/0xc0 net/socket.c:322
alloc_inode+0x6a/0x1b0 fs/inode.c:346
new_inode_pseudo include/linux/fs.h:2963 [inline]
sock_alloc net/socket.c:637 [inline]
do_accept+0x114/0x7f0 net/socket.c:1980
io_accept+0x307/0x790 io_uring/net.c:1665
__io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1792
io_poll_issue+0x12d/0x1f0 io_uring/io_uring.c:1849
io_poll_check_events io_uring/poll.c:307 [inline]
io_poll_task_func+0x32f/0xd10 io_uring/poll.c:336
io_handle_tw_list+0x263/0x550 io_uring/io_uring.c:1121
tctx_task_work_run+0x55/0x2c0 io_uring/io_uring.c:1181
tctx_task_work+0x3f/0x90 io_uring/io_uring.c:1199
task_work_run+0x1d4/0x260 kernel/task_work.c:233
get_signal+0x11ec/0x1340 kernel/signal.c:2807
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc3c258f749
RSP: 002b:00007fc3c33e3038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: 0000000000000200 RBX: 00007fc3c27e5fa0 RCX: 00007fc3c258f749
RDX: 0000000000000000 RSI: 00000000000047f5 RDI: 0000000000000007
RBP: 00007fc3c2613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc3c27e6038 R14: 00007fc3c27e5fa0 R15: 00007ffc5ea87bd8
rcu: rcu_preempt kthread starved for 10426 jiffies! g30789 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:26200 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
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+0x599/0xb30 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 9e 2a 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0000:ffffc90000197de0 EFLAGS: 000002c6
RAX: 58c97fbe07903800 RBX: ffffffff819786ba RCX: 58c97fbe07903800
RDX: 0000000000000001 RSI: ffffffff8d997e54 RDI: ffffffff8be07960
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fa22f70
R13: 1ffff11003addb70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0dbceed6c8 CR3: 00000000319b0000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147