rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8120/5:b..l
rcu: (detected by 0, t=10502 jiffies, g=55653, q=180 ncpus=2)
task:syz-executor state:R running task stack:21208 pid:8120 tgid:8120 ppid:8111 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x169e/0x54f0 kernel/sched/core.c:7188
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x730 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5874
Code: ff ff ff e8 b1 f2 95 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 8b ed d5 10 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 28 fc ef
RSP: 0018:ffffc900049e7288 EFLAGS: 00000286
RAX: d4685a13b47c2e00 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000dbd1ab37 RSI: ffffffff8d8b3bc3 RDI: ffffffff8ba84960
RBP: ffffffff82353b56 R08: ffffffff82353b56 R09: ffffffff8dfc8100
R10: dffffc0000000000 R11: fffff94000464ce9 R12: 0000000000000002
R13: ffffffff8dfc8100 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
page_table_check_set+0x143/0x510 mm/page_table_check.c:112
page_table_check_ptes_set include/linux/page_table_check.h:83 [inline]
set_ptes include/linux/pgtable.h:413 [inline]
__copy_present_ptes mm/memory.c:1102 [inline]
copy_present_ptes mm/memory.c:1181 [inline]
copy_pte_range mm/memory.c:1304 [inline]
copy_pmd_range+0x350b/0x5550 mm/memory.c:1392
copy_pud_range mm/memory.c:1429 [inline]
copy_p4d_range mm/memory.c:1453 [inline]
copy_page_range+0xaf4/0x1120 mm/memory.c:1539
dup_mmap+0xf4c/0x1d50 mm/mmap.c:1840
dup_mm kernel/fork.c:1534 [inline]
copy_mm+0x13b/0x4a0 kernel/fork.c:1586
copy_process+0x1f24/0x4460 kernel/fork.c:2262
kernel_clone+0x2d7/0x940 kernel/fork.c:2724
__do_sys_clone kernel/fork.c:2865 [inline]
__se_sys_clone kernel/fork.c:2849 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2849
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f34d9345292
RSP: 002b:00007ffd06ed7b40 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffd06ed7b40 RCX: 00007f34d9345292
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffd06ed7ccc R08: 0000000000000000 R09: 0000000000000001
R10: 000055557bcc67d0 R11: 0000000000000246 R12: 0000000000000001
R13: 000055557bcd99f0 R14: 000000000008f033 R15: 00007ffd06ed7d20
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g55653 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=27188
rcu: rcu_preempt kthread starved for 10502 jiffies! g55653 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27480 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x169e/0x54f0 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7282
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11b0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9382 Comm: iou-sqp-9381 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:check_preemption_disabled+0x29/0xe0 lib/smp_processor_id.c:19
Code: 90 55 41 57 41 56 53 65 8b 05 a7 df 3f 07 65 8b 0d 9c df 3f 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d c3 cc cc cc cc cc 9c <59> f7 c1 00 02 00 00 74 ea 65 4c 8b 3d 4e df 3f 07 41 f6 47 2f 04
RSP: 0018:ffffc90003fd7a70 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 00000000ffffffff RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff8d66989f RDI: ffffffff8ba84960
RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100742eb89 R12: 0000000000000246
R13: ffff88803a175c40 R14: ffff88805d41c4d8 R15: dffffc0000000000
FS: 00007f54052b66c0(0000) GS:ffff888125fba000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000bbdffc CR3: 00000000374c8000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
lock_is_held_type+0x5a/0x150 kernel/locking/lockdep.c:5941
lock_is_held include/linux/lockdep.h:249 [inline]
io_get_rings io_uring/io_uring.h:147 [inline]
__io_sqring_entries io_uring/io_uring.h:469 [inline]
io_sqring_entries+0x10f/0x300 io_uring/io_uring.h:480
__io_sq_thread io_uring/sqpoll.c:210 [inline]
io_sq_thread+0x996/0x1d60 io_uring/sqpoll.c:345
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245