rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=8957, q=44 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10498 (4294956061-4294945563), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10498 jiffies! g8957 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:26728 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 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:
CPU: 1 PID: 5811 Comm: syz-executor167 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lock_acquire+0x81/0x410 kernel/locking/lockdep.c:5722
Code: 41 48 c7 44 24 68 53 95 59 8c 48 c7 44 24 70 20 08 67 81 4c 8d 64 24 60 49 c1 ec 03 48 b8 f1 f1 f1 f1 00 f2 f2 f2 4b 89 04 3c <66> 43 c7 44 3c 09 f3 f3 43 c6 44 3c 0b f3 0f 1f 44 00 00 65 8b 05
RSP: 0018:ffffc9000482fb80 EFLAGS: 00000a02
RAX: f2f2f200f1f1f1f1 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880780c6a20
RBP: ffffc9000482fc88 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000482fd60 R11: fffff52000905fcc R12: 1ffff92000905f7c
R13: ffff8880780c6a20 R14: ffffffff81c8efea R15: dffffc0000000000
FS:  0000555558a2e3c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f15232abf10 CR3: 000000002f2b4000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 __might_fault+0xc6/0x120 mm/memory.c:5946
 _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: 0033:0x7f15232abf19
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:00007ffdcf57f240 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f15232abf19
RDX: 00007ffdcf57f240 RSI: 00007ffdcf57f370 RDI: 0000000000000021
RBP: 0000000000000000 R08: 00007f1523254990 R09: 00007f1523254990
R10: 0000000000000000 R11: 0000000000000206 R12: 00007f15232f233c
R13: 00007f15232ec106 R14: 00007ffdcf57f800 R15: 0000000000000000
 </TASK>