rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10506 jiffies, g=37213, q=103 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295000172-4294989670), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g37213 f0x2 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:26280 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
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: 9144 Comm: syz.0.709 Not tainted 6.15.0-rc7-next-20250522-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:153 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x93/0x110 kernel/locking/spinlock.c:194
Code: 75 08 e8 40 95 37 f6 4c 89 f7 e8 98 2c 38 f6 f7 c3 00 02 00 00 74 05 e8 cb 27 61 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 <f6> 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e8
RSP: 0018:ffffc90000a08be0 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000802 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff99d47560
RBP: ffffc90000a08c78 R08: ffffffff99d47563 R09: 1ffffffff33a8eac
R10: dffffc0000000000 R11: fffffbfff33a8ead R12: dffffc0000000000
R13: ffff88807a0c5d20 R14: ffffffff99d47560 R15: 1ffff9200014117c
FS:  00007ff75e2286c0(0000) GS:ffff888125d59000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30507ff8 CR3: 0000000079e3a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 debug_object_activate+0x2e2/0x420 lib/debugobjects.c:836
 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+0x10b/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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 fb 4d fe 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003657448 EFLAGS: 00000206
RAX: 84a3c36ce883ce00 RBX: 0000000000000000 RCX: 84a3c36ce883ce00
RDX: 0000000000000001 RSI: ffffffff8db6a54c RDI: ffffffff8be29000
RBP: ffffffff8b653371 R08: 0000000000000000 R09: ffffffff8b653371
R10: dffffc0000000000 R11: ffffed10037d25fe R12: 0000000000000000
R13: ffffffff8dffafa0 R14: 0000000000000001 R15: 0000000000000246
 sched_submit_work kernel/sched/core.c:6819 [inline]
 schedule+0xb1/0x360 kernel/sched/core.c:6877
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 unix_wait_for_peer+0x1e9/0x2e0 net/unix/af_unix.c:1581
 unix_dgram_sendmsg+0xbda/0x17c0 net/unix/af_unix.c:2201
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:727
 ____sys_sendmsg+0x52d/0x830 net/socket.c:2566
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
 __sys_sendmmsg+0x227/0x430 net/socket.c:2709
 __do_sys_sendmmsg net/socket.c:2736 [inline]
 __se_sys_sendmmsg net/socket.c:2733 [inline]
 __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2733
 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: 0033:0x7ff75d38e969
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:00007ff75e228038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007ff75d5b5fa0 RCX: 00007ff75d38e969
RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000006
RBP: 00007ff75d410ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff75d5b5fa0 R15: 00007ffd67fbc988
 </TASK>