rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=19793, q=655 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294962538-4294952035), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g19793 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:27496 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14e2/0x4580 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 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: 6779 Comm: syz.0.32 Not tainted 6.6.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lock_release+0x11/0x8b0 kernel/locking/lockdep.c:5762
Code: e9 0e fa ff ff bb 2f 00 00 00 e9 24 fa ff ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 <48> 83 e4 e0 48 81 ec e0 00 00 00 49 89 f4 48 89 7c 24 18 65 48 8b
RSP: 0018:ffffc90003947ca0 EFLAGS: 00000286
RAX: 75a3abc271985f00 RBX: 00000000000000c0 RCX: 75a3abc271985f00
RDX: 0000000000000000 RSI: ffffffff81ca54ca RDI: ffff888031cd27a0
RBP: ffffc90003947cc8 R08: dffffc0000000000 R09: 1ffffffff21b0aaa
R10: dffffc0000000000 R11: fffffbfff21b0aab R12: ffffc90003947d60
R13: 1ffff92000728ffe R14: ffffc90003947d60 R15: 00007fb07022aae8
FS:  00007fb07022b6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 00000000732ab000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 _copy_from_user+0x2a/0xe0 lib/usercopy.c:14
 copy_from_user include/linux/uaccess.h:183 [inline]
 restore_sigcontext arch/x86/kernel/signal_64.c:59 [inline]
 __ia32_sys_rt_sigreturn+0x27a/0x7b0 arch/x86/kernel/signal_64.c:266
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb06f32ab19
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007fb07022aac0 EFLAGS: 00000202 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007fb06f5b5fa0 RCX: 00007fb06f32ab19
RDX: 00007fb07022aac0 RSI: 00007fb07022abf0 RDI: 0000000000000021
RBP: 00007fb06f410b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb06f5b5fa0 R15: 00007ffd3d5b34c8
 </TASK>