rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3624/1:b..l P4255/1:b..l P4250/1:b..l
	(detected by 1, t=10503 jiffies, g=9673, q=81 ncpus=2)
task:syz-executor    state:R  running task     stack:21112 pid:4250  ppid:4247   flags:0x00004000
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_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:step_into+0x2b6/0x1070 fs/namei.c:1840
Code: 64 24 40 43 80 3c 34 00 74 08 48 89 df e8 32 de ec ff 4c 8b bc 24 d8 00 00 00 49 8d 7f 68 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <4c> 8d a4 24 d0 00 00 00 74 05 e8 0b de ec ff 49 8b 47 68 48 89 44
RSP: 0018:ffffc90003d97820 EFLAGS: 00000246
RAX: 1ffff1100ababcc9 RBX: ffffc90003d978f8 RCX: ffff88807d779dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888055d5e648
RBP: ffffc90003d97970 R08: ffffffff81f53547 R09: fffffbfff1d4168e
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920007b2f1f
R13: ffffc90003d97ba0 R14: dffffc0000000000 R15: ffff888055d5e5e0
 walk_component fs/namei.c:2004 [inline]
 link_path_walk+0x72c/0xee0 fs/namei.c:2325
 path_lookupat+0xa9/0x450 fs/namei.c:2478
 filename_lookup+0x251/0x600 fs/namei.c:2508
 user_path_at_empty+0x3e/0x60 fs/namei.c:2905
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_pivot_root fs/namespace.c:3900 [inline]
 __se_sys_pivot_root+0x1db/0x1640 fs/namespace.c:3884
 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: 0033:0x7f206a18d169
RSP: 002b:00007ffd2be03aa8 EFLAGS: 00000246 ORIG_RAX: 000000000000009b
RAX: ffffffffffffffda RBX: 00007f206a20e678 RCX: 00007f206a18d169
RDX: 00007f206a18b9d7 RSI: 00007f206a20e8ac RDI: 00007f206a20e678
RBP: 00007f206a20e8ac R08: 0000000000000000 R09: 00007f206a3a6738
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f206a1eb1a8
R13: 00007f206a1eb180 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
task:syz-executor    state:R  running task     stack:20728 pid:4255  ppid:4248   flags:0x00004000
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_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:debug_lockdep_rcu_enabled+0x9/0x30 kernel/rcu/update.c:280
Code: c7 e0 1b 0c 8b 48 c7 c6 00 40 0c 8b e8 60 38 a1 f6 0f 0b eb d0 cc cc cc cc cc cc cc cc cc cc cc cc 31 c0 83 3d f7 2d ef 03 00 <74> 1d 83 3d 92 61 ef 03 00 74 14 65 48 8b 0d 94 e7 50 75 31 c0 83
RSP: 0018:ffffc90003d77718 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff88807e756a80 RCX: ffffc90003d77603
RDX: 0000000000000004 RSI: ffffffff8b0c2ec0 RDI: ffffffff8b5f6f80
RBP: 0000000000000cc0 R08: dffffc0000000000 R09: fffffbfff1d4168e
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff888140008b40 R14: ffffffff81e915c4 R15: dffffc0000000000
 rcu_read_unlock include/linux/rcupdate.h:820 [inline]
 get_obj_cgroup_from_current+0x178/0x280 mm/memcontrol.c:3027
 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
 vm_area_dup+0x23/0x1b0 kernel/fork.c:467
 dup_mmap kernel/fork.c:646 [inline]
 dup_mm kernel/fork.c:1541 [inline]
 copy_mm+0xbbc/0x1990 kernel/fork.c:1590
 copy_process+0x19fb/0x40a0 kernel/fork.c:2266
 kernel_clone+0x222/0x920 kernel/fork.c:2681
 __do_sys_clone kernel/fork.c:2822 [inline]
 __se_sys_clone kernel/fork.c:2806 [inline]
 __x64_sys_clone+0x242/0x2c0 kernel/fork.c:2806
 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: 0033:0x7fc73c5839d3
RSP: 002b:00007ffe2d92ce68 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc73c5839d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055555d3407d0 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000005c R14: 00000000000170f1 R15: 00007ffe2d92d000
 </TASK>
task:udevd           state:R  running task     stack:24776 pid:3624  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_common+0x83/0xd0 kernel/sched/core.c:6729
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6753
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 __d_lookup+0x61b/0x790 fs/dcache.c:2506
 lookup_fast+0x74/0x490 fs/namei.c:1648
 walk_component fs/namei.c:1994 [inline]
 link_path_walk+0x604/0xee0 fs/namei.c:2325
 path_lookupat+0xa9/0x450 fs/namei.c:2478
 filename_lookup+0x251/0x600 fs/namei.c:2508
 user_path_at_empty+0x3e/0x60 fs/namei.c:2905
 do_readlinkat+0x114/0x3a0 fs/stat.c:468
 __do_sys_readlink fs/stat.c:501 [inline]
 __se_sys_readlink fs/stat.c:498 [inline]
 __x64_sys_readlink+0x7b/0x90 fs/stat.c:498
 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: 0033:0x7f94a8117d47
RSP: 002b:00007ffd8b836768 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffd8b836778 RCX: 00007f94a8117d47
RDX: 0000000000000400 RSI: 00007ffd8b836778 RDI: 00007ffd8b836c58
RBP: 0000000000000400 R08: 000055caa31bcd84 R09: 0000000000000000
R10: 0000000000000812 R11: 0000000000000246 R12: 00007ffd8b836c58
R13: 00007ffd8b836bc8 R14: 000055caa31b1910 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10594 jiffies! g9673 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:26200 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4357 Comm: syz.0.7 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:215
Code: 00 0f 0b 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d e8 0c 16 0d 48 89 de 5b e9 67 8a 56 00 cc cc cc cc cc cc cc 48 8b 04 24 <65> 48 8b 0d 74 c5 77 7e 65 8b 15 75 c5 77 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90000007e38 EFLAGS: 00000046
RAX: ffffffff817a1980 RBX: 0000000000000000 RCX: ffff88802a723b80
RDX: ffff88802a723b80 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000002f2a1ce680 R08: ffffffff817ce553 R09: ffffffff817ce4fc
R10: 0000000000000002 R11: ffff88802a723b80 R12: ffff8880b8e271c0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8e2a8a8
FS:  00007f77b28d26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d61fffc CR3: 0000000029672000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 ktime_get+0x10/0x270 kernel/time/timekeeping.c:837
 clockevents_program_event+0xe1/0x310 kernel/time/clockevents.c:326
 hrtimer_interrupt+0x546/0x980 kernel/time/hrtimer.c:1828
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: a1 84 f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e dc ae f6 48 89 df e8 f6 1a b0 f6 e8 51 6d d5 f6 fb bf 01 00 00 00 <e8> d6 9b a2 f6 65 8b 05 f7 71 46 75 85 c0 74 02 5b c3 e8 94 95 44
RSP: 0018:ffffc9000461fb30 EFLAGS: 00000286
RAX: ea1b9079c159c200 RBX: ffff88802f9ddc80 RCX: ffffffff973c0103
RDX: dffffc0000000000 RSI: ffffffff8b0c1d40 RDI: 0000000000000001
RBP: ffffc9000461fc70 R08: dffffc0000000000 R09: ffffed1005f3bb91
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11005f3bc23
R13: 000000001c000004 R14: 0000000000000021 R15: ffff88802f9de118
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x151f/0x17a0 kernel/signal.c:2874
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f77b198d167
Code: ff ff 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
RSP: 002b:00007f77b28d20e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f77b1ba5fa8 RCX: 00007f77b198d169
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f77b1ba5fa8
RBP: 00007f77b1ba5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f77b1ba5fac
R13: 0000000000000000 R14: 00007fff95c78180 R15: 00007fff95c78268
 </TASK>
sched: RT throttling activated