syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=38597, q=9 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294979441-4294968939), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g38597 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:26776 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:preempt_count_add+0x2/0x180 kernel/sched/core.c:5698
Code: 0c 24 80 e1 07 80 c1 03 38 c1 7c 97 48 8b 3c 24 e8 d3 b2 83 00 eb 8c e9 f2 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 <41> 56 53 89 fb 48 c7 c0 60 51 c9 91 48 c1 e8 03 49 bf 00 00 00 00
RSP: 0018:ffffc90000157b88 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 1ffff11027fd5b28 RCX: ffffffff8a939aa6
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
RBP: ffffc90000157cb0 R08: dffffc0000000000 R09: ffffed1027fd5b29
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fead940
R13: 1ffff9200002af78 R14: ffff88813feaebb8 R15: dffffc0000000000
 schedule+0xb8/0x180 kernel/sched/core.c:6633
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 7247 Comm: syz-executor.0 Not tainted 6.1.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124
Code: 2e 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 7b 23 36 09 e8 06 1e 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28
RSP: 0018:ffffc90003a7f8a8 EFLAGS: 00000286
RAX: 2bc643ca0a6b8a00 RBX: ffff8880282ad974 RCX: ffffffff91c95103
RDX: dffffc0000000000 RSI: ffffffff8aec0240 RDI: ffff88802711d178
RBP: ffffc90003a7f8f0 R08: dffffc0000000000 R09: ffffed1017307541
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802711bb80
R13: 1ffff110173076eb R14: ffff8880b983aa00 R15: ffff8880b983b758
FS:  00007fbbc09106c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2c439000 CR3: 000000004b286000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x1435/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 futex_wait_queue+0x149/0x1d0 kernel/futex/waitwake.c:355
 futex_wait+0x203/0x5c0 kernel/futex/waitwake.c:656
 do_futex+0x3b5/0x490 kernel/futex/syscalls.c:106
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex+0x3d7/0x460 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbbbfc7d0a9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbbc0910178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fbbbfdb4128 RCX: 00007fbbbfc7d0a9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fbbbfdb4128
RBP: 00007fbbbfdb4120 R08: 00007fbbc09106c0 R09: 00007fbbc09106c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbbbfdb412c
R13: 000000000000006e R14: 00007ffe9edc4540 R15: 00007ffe9edc4628
 </TASK>