syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=3c4c/1/0x4000000000000000 softirq=81288/81289 fqs=1
rcu: 	(detected by 1, t=10506 jiffies, g=104093, q=114 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 17181 Comm: syz.4.3882 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:arch_atomic_set arch/x86/include/asm/atomic.h:28 [inline]
RIP: 0010:raw_atomic_set include/linux/atomic/atomic-arch-fallback.h:490 [inline]
RIP: 0010:atomic_set include/linux/atomic/atomic-instrumented.h:68 [inline]
RIP: 0010:taprio_set_budgets+0x240/0x390 net/sched/sch_taprio.c:688
Code: e8 75 19 e8 f8 49 83 fc 10 77 69 e8 2a 15 e8 f8 49 8d ac 1f 80 00 00 00 48 89 ef be 04 00 00 00 e8 f5 6f 3f f9 48 8b 44 24 28 <48> 8d 3c 18 48 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f
RSP: 0018:ffffc90000007c00 EFLAGS: 00000056
RAX: ffff88802eadd080 RBX: 0000000000000000 RCX: ffffffff889d75bb
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88802eadd080
RBP: ffff88802eadd080 R08: ffff88802eadd083 R09: 1ffff11005d5ba10
R10: dffffc0000000000 R11: ffffed1005d5ba11 R12: 0000000000000000
R13: 0000000000000000 R14: ffff888078eb42e0 R15: ffff88802eadd000
FS:  00007fb343b636c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33a23ffc CR3: 000000006b990000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 advance_sched+0x964/0xc80 net/sched/sch_taprio.c:993
 __run_hrtimer kernel/time/hrtimer.c:1750 [inline]
 __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1814
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 ba cc 13 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 92 4b e3 f6 65 8b 05 73 96 8b 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000c107140 EFLAGS: 00000206
RAX: 5ed7c2c743a71a00 RBX: 0000000000000a06 RCX: 5ed7c2c743a71a00
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001
RBP: ffffc9000c1071c8 R08: ffffffff90da76a7 R09: 1ffffffff21b4ed4
R10: dffffc0000000000 R11: fffffbfff21b4ed5 R12: dffffc0000000000
R13: ffff88807600c000 R14: ffff888017840a80 R15: 1ffff92001820e28
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 get_partial_node+0x4ff/0x540 mm/slub.c:2338
 get_partial mm/slub.c:2416 [inline]
 ___slab_alloc+0x9cd/0x1300 mm/slub.c:3230
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc+0xa4/0x240 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 get_mem_for_virtual_node fs/reiserfs/fix_node.c:2286 [inline]
 fix_nodes+0x6034/0x82e0 fs/reiserfs/fix_node.c:2626
 reiserfs_cut_from_item+0x309/0x1f10 fs/reiserfs/stree.c:1740
 reiserfs_rmdir+0x3bc/0x730 fs/reiserfs/namei.c:957
 vfs_rmdir+0x370/0x4d0 fs/namei.c:4196
 do_rmdir+0x29e/0x5c0 fs/namei.c:4255
 __do_sys_unlinkat fs/namei.c:4433 [inline]
 __se_sys_unlinkat fs/namei.c:4427 [inline]
 __x64_sys_unlinkat+0xc4/0xe0 fs/namei.c:4427
 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: 0033:0x7fb342d8efc9
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:00007fb343b63038 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007fb342fe5fa0 RCX: 00007fb342d8efc9
RDX: 0000000000000200 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007fb342e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb342fe6038 R14: 00007fb342fe5fa0 R15: 00007ffd9b3be3d8
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g104093 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:26728 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 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: 2976 Comm: kworker/u4:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xddf/0x1130 kernel/smp.c:855
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 da d6 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 15 d3 0a 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 f9 d2
RSP: 0000:ffffc9000ba67780 EFLAGS: 00000293
RAX: ffffffff817ab7d7 RBX: 1ffff110171c8791 RCX: ffff88802b9b8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000ba67900 R08: ffffffff90da7507 R09: 1ffffffff21b4ea0
R10: dffffc0000000000 R11: fffffbfff21b4ea1 R12: ffff8880b8e43c88
R13: dffffc0000000000 R14: ffff8880b8f3d348 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6079238000 CR3: 000000000cb30000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
 text_poke_bp_batch+0x318/0x930 arch/x86/kernel/alternative.c:2432
 text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
 static_key_enable+0x1a/0x20 kernel/jump_label.c:220
 toggle_allocation_gate+0xaa/0x250 mm/kfence/core.c:831
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 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>