rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=4a24/1/0x4000000000000000 softirq=69497/69498 fqs=2 (t=10501 jiffies g=95185 q=187 ncpus=2) rcu: rcu_preempt kthread starved for 10498 jiffies! g95185 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:26080 pid:16 ppid:2 flags:0x00004000 Call Trace: 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 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 17904 Comm: syz.4.3446 Not tainted 6.1.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:mark_lock+0xa2/0x340 kernel/locking/lockdep.c:4606 Code: 00 8b 1b 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 60 92 2b 91 be 08 00 00 00 e8 f6 e7 76 00 48 0f a3 1d be 6d c0 0f <73> 11 48 8d 04 5b 48 c1 e0 06 48 8d 98 20 11 c4 90 eb 23 48 c7 c0 RSP: 0018:ffffc900001e0af8 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000048 RCX: ffffffff816b249a RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff912b9268 RBP: 0000000000000009 R08: dffffc0000000000 R09: fffffbfff225724e R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888072886418 R13: dffffc0000000000 R14: 0000000000000200 R15: ffff888072886420 FS: 00007f3dcfe2d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 0000000027bdb000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4549 [inline] __lock_acquire+0xc6a/0x1f80 kernel/locking/lockdep.c:5003 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 seqcount_lockdep_reader_access+0xf8/0x220 include/linux/seqlock.h:102 ktime_get+0x31/0x270 kernel/time/timekeeping.c:846 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 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 d6 9b a2 f6 65 8b 05 f7 71 46 75 85 c0 74 02 5b c3 e8 94 95 44 RSP: 0018:ffffc90004077b30 EFLAGS: 00000286 RAX: 209c31d92f3c8000 RBX: ffff8880561ac0c0 RCX: ffffffff973c0103 RDX: dffffc0000000000 RSI: ffffffff8b0c1d40 RDI: 0000000000000001 RBP: ffffc90004077c70 R08: dffffc0000000000 R09: ffffed100ac35819 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1100ac358ab R13: 000000001c000004 R14: 0000000000000021 R15: ffff8880561ac558 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: 0033:0x7f3dcef8d167 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:00007f3dcfe2d038 EFLAGS: 00000246 RAX: 0000000000000113 RBX: 00007f3dcf1a5fa0 RCX: 00007f3dcef8d169 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f3dcf00e2a0 R08: 0000000008000f28 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3dcf1a5fa0 R15: 00007ffffb2500f8 CPU: 0 PID: 17912 Comm: syz.5.3447 Not tainted 6.1.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:lock_release+0x20/0xa20 kernel/locking/lockdep.c:5670 Code: e9 66 fd ff ff 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 00 01 00 00 49 89 f5 48 89 7c 24 18 <65> 48 8b 04 25 28 00 00 00 48 89 84 24 e0 00 00 00 49 bf 00 00 00 RSP: 0018:ffffc9000346fb00 EFLAGS: 00000286 RAX: 44867649a3c1a300 RBX: ffffc9000346fe00 RCX: ffffffff816b7142 RDX: dffffc0000000000 RSI: ffffffff81cdb301 RDI: ffff88807d9a7958 RBP: ffffc9000346fc28 R08: dffffc0000000000 R09: fffffbfff2257253 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000030 R13: ffffffff81cdb301 R14: 00007fb6d7642c70 R15: ffffc9000346fe00 FS: 00007fb6d76436c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2df06ff8 CR3: 000000007ba87000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: _copy_to_user+0x26/0x130 lib/usercopy.c:36 copy_to_user include/linux/uaccess.h:169 [inline] copy_siginfo_to_user+0x20/0x140 kernel/signal.c:3339 __setup_rt_frame arch/x86/kernel/signal.c:491 [inline] setup_rt_frame arch/x86/kernel/signal.c:784 [inline] handle_signal arch/x86/kernel/signal.c:828 [inline] arch_do_signal_or_restart+0xb99/0x1a10 arch/x86/kernel/signal.c:873 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: 0033:0x7fb6d678d167 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:00007fb6d76430e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007fb6d69a5fa8 RCX: 00007fb6d678d169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb6d69a5fa8 RBP: 00007fb6d69a5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb6d69a5fac R13: 0000000000000000 R14: 00007ffd44500c80 R15: 00007ffd44500d68