syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3625/1:b..l
	(detected by 0, t=10502 jiffies, g=22273, q=110 ncpus=2)
task:udevd           state:R  running task     stack:22760 pid:3625  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666
Code: 2b 00 74 08 4c 89 f7 e8 9f 49 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc90003257580 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff9200064aebc RCX: 1ffff9200064ae5c
RDX: dffffc0000000000 RSI: ffffffff8b0c2ec0 RDI: ffffffff8b5f6d80
RBP: ffffc900032576d0 R08: dffffc0000000000 R09: fffffbfff2256c4d
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200064aeb8
R13: dffffc0000000000 R14: ffffc900032575e0 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 get_obj_cgroup_from_current+0xf1/0x280 mm/memcontrol.c:3016
 memcg_slab_pre_alloc_hook mm/slab.h:485 [inline]
 slab_pre_alloc_hook+0x90/0x300 mm/slab.h:715
 slab_alloc_node mm/slub.c:3318 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x4e/0x2d0 mm/slub.c:3422
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 seq_open+0x5e/0x130 fs/seq_file.c:63
 kernfs_fop_open+0x5fe/0xcc0
 do_dentry_open+0x7f9/0x10f0 fs/open.c:882
 do_open fs/namei.c:3626 [inline]
 path_openat+0x2644/0x2e60 fs/namei.c:3783
 do_filp_open+0x230/0x480 fs/namei.c:3810
 do_sys_openat2+0x13b/0x4f0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1345
 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: 0033:0x7ffb457169a4
RSP: 002b:00007ffe8d4d47a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007ffb457169a4
RDX: 0000000000080000 RSI: 00007ffe8d4d48d8 RDI: 00000000ffffff9c
RBP: 00007ffe8d4d48d8 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000
R13: 00005632c3ce0b42 R14: 0000000000000001 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 9232 jiffies! g22273 f0x0 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:26712 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 schedule+0xbf/0x180 kernel/sched/core.c:6636
 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:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567
Code: 47 cf f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 b4 04 d6 f6 0f 1f 44 00 00 e8 da 43 cf f6 0f 00 2d e3 62 ae 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 7b 9c 26 f7
RSP: 0018:ffffffff8d007b20 EFLAGS: 000002d3
RAX: ffffffff8abb52f6 RBX: 0000000000000000 RCX: ffffffff8d0bd980
RDX: 0000000000000000 RSI: ffffffff8b0c1d40 RDI: ffffffff8b5f6d80
RBP: ffffffff8d007bb0 R08: ffffffff8abb52d8 R09: fffffbfff1a17b31
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1a00f64
R13: ffff88814728c004 R14: ffffffff8d007b40 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffa9d0856c0 CR3: 00000000292e4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:704
 cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239
 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356
 call_cpuidle kernel/sched/idle.c:155 [inline]
 cpuidle_idle_call kernel/sched/idle.c:236 [inline]
 do_idle+0x3ce/0x680 kernel/sched/idle.c:303
 cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401
 rest_init+0x2da/0x300 init/main.c:733
 arch_call_rest_init+0xa/0xa init/main.c:893
 start_kernel+0x496/0x53f init/main.c:1140
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>