rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=caac/1/0x4000000000000000 softirq=15993/15994 fqs=1
rcu: 	(detected by 1, t=10506 jiffies, g=13417, q=134 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5985 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid kernel/sched/sched.h:3837 [inline]
RIP: 0010:sched_mm_cid_fork+0x56c/0xc80 kernel/sched/core.c:10704
Code: 00 00 0f b6 c0 41 29 c6 4c 89 e3 e9 64 ff ff ff 49 c7 c5 98 1e 2c 8e 49 c1 ed 03 eb 0b 44 89 e0 f7 d8 0f 81 2a fd ff ff f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 50 44 8b
RSP: 0018:ffffc90003857c78 EFLAGS: 00000887
RAX: 0000000080000000 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff88807c1bbc90
RBP: ffff88807c1bbc90 R08: 1ffff1100f837641 R09: 0000000000000000
R10: ffff88807c1bb34c R11: fffff5200070af80 R12: 0000000080000000
R13: 1ffffffff1c583d3 R14: 0000000000000002 R15: ffff88807c1bb100
FS:  00007f3a35ff66c0(0000) GS:ffff888125015000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005584f466a660 CR3: 0000000076e10000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 bprm_execve+0xda1/0x1460 fs/exec.c:1771
 do_execveat_common+0x50d/0x690 fs/exec.c:1846
 __do_sys_execveat fs/exec.c:1941 [inline]
 __se_sys_execveat fs/exec.c:1934 [inline]
 __x64_sys_execveat+0xc7/0xf0 fs/exec.c:1934
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3a3519aeb9
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:00007f3a35ff6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007f3a35415fa0 RCX: 00007f3a3519aeb9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007f3a35208c1f R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3a35416038 R14: 00007f3a35415fa0 R15: 00007ffdb92a42b8
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g13417 f0x0 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:28128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x1585/0x5310 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7004
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xce5/0x12c0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 34 e3 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 df de 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 c3 de
RSP: 0018:ffffc90000117760 EFLAGS: 00000293
RAX: ffffffff81ba0f0d RBX: 1ffff11017088515 RCX: ffff88801dab8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900001178a0 R08: ffffffff903342b7 R09: 1ffffffff2066856
R10: dffffc0000000000 R11: fffffbfff2066857 R12: ffff8880b84428a8
R13: dffffc0000000000 R14: ffff8880b853bf80 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125115000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558509645168 CR3: 000000000e74c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
 on_each_cpu include/linux/smp.h:72 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2746 [inline]
 smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2956
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:899
 process_one_work+0x949/0x1650 kernel/workqueue.c:3279
 process_scheduled_works kernel/workqueue.c:3362 [inline]
 worker_thread+0xb46/0x1140 kernel/workqueue.c:3443
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>