rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=13369, q=681 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294959386-4294948886), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10500 jiffies! g13369 f0x2 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:26920 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6003 Comm: syz.2.27 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:mark_lock+0x9c/0x320 kernel/locking/lockdep.c:4656
Code: 89 c7 41 81 e7 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 00 f5 1b 91 be 08 00 00 00 e8 fc 5e 76 00 4c 0f a3 3d 94 14 b3 0f <73> 10 49 69 c7 d0 00 00 00 4c 8d b8 c0 73 b2 90 eb 24 48 c7 c0 80
RSP: 0018:ffffc900035777c0 EFLAGS: 00000057
RAX: 0000000000000001 RBX: ffff88802ce41e00 RCX: ffffffff8168e064
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911bf530
RBP: 0000000000000003 R08: ffffffff911bf537 R09: 1ffffffff2237ea6
R10: dffffc0000000000 R11: fffffbfff2237ea7 R12: 0000000000000008
R13: dffffc0000000000 R14: ffff88802ce428e0 R15: 00000000000001ad
FS:  00007f66a95aa6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000007b388000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 mark_usage kernel/locking/lockdep.c:4579 [inline]
 __lock_acquire+0x111e/0x7d40 kernel/locking/lockdep.c:5091
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __might_fault+0xc6/0x120 mm/memory.c:5968
 __clear_user arch/x86/include/asm/uaccess_64.h:167 [inline]
 clear_user arch/x86/include/asm/uaccess_64.h:191 [inline]
 copy_siginfo_to_user+0x5b/0xa0 kernel/signal.c:3374
 x64_setup_rt_frame+0x746/0xc40 arch/x86/kernel/signal_64.c:194
 setup_rt_frame arch/x86/kernel/signal.c:223 [inline]
 handle_signal arch/x86/kernel/signal.c:267 [inline]
 arch_do_signal_or_restart+0x42c/0x800 arch/x86/kernel/signal.c:312
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f66a879aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f66a95aa0e8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f66a8a15fa8 RCX: 00007f66a879aeb9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f66a8a15fac
RBP: 00007f66a8a15fa0 R08: 0000000000745d1e R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f66a8a16038 R14: 00007ffccd89a260 R15: 00007ffccd89a348
 </TASK>