rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=c38c/1/0x4000000000000000 softirq=8546/8555 fqs=0 (t=10502 jiffies g=7689 q=81 ncpus=2) rcu: rcu_preempt kthread starved for 10503 jiffies! g7689 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:28192 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4268 Comm: syz-executor325 Not tainted 6.1.141-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212 Code: 2e 0f 1f 84 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 70 b1 7d 0c 48 89 de 5b e9 c7 af 50 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d c4 98 81 7e 65 8b 15 c5 98 81 7e 81 e2 00 RSP: 0018:ffffc90000007e90 EFLAGS: 00000097 RAX: ffffffff8170e2aa RBX: ffff8880b8e2a580 RCX: ffff88801ee69dc0 RDX: 0000000000010000 RSI: 7fffffffffffffff RDI: 0000002c25a0ab38 RBP: 0000002c25a0ab38 R08: dffffc0000000000 R09: fffffbfff1bfd0b6 R10: fffffbfff1bfd0b6 R11: 1ffffffff1bfd0b5 R12: 7fffffffffffffff R13: ffff8880b8e2a5f0 R14: dffffc0000000000 R15: 0000000000000011 FS: 00007fb6affa36c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb6affa2e40 CR3: 000000007c16f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: hrtimer_interrupt+0x354/0x9c0 kernel/time/hrtimer.c:1872 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 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: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 de d0 49 f7 48 89 df e8 36 96 4a f7 e8 31 97 6d f7 fb bf 01 00 00 00 46 13 3e f7 65 8b 05 17 d4 e8 75 85 c0 74 02 5b c3 e8 64 e5 e6 RSP: 0018:ffffc90003d67bb8 EFLAGS: 00000286 RAX: 50b930d7823cc800 RBX: ffff88802f225340 RCX: 50b930d7823cc800 RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: 0000000000000001 RBP: ffff88802f2257d8 R08: dffffc0000000000 R09: ffffed1005e44a69 R10: ffffed1005e44a69 R11: 1ffff11005e44a68 R12: 1ffff11005e44afb R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1163/0x1350 kernel/signal.c:2874 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 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+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb6affe2697 Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 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 RSP: 002b:00007fb6affa3218 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007fb6b006c308 RCX: 00007fb6affe2699 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb6b006c308 RBP: 00007fb6b006c300 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000140 R13: 000020000006b000 R14: 0000200000000100 R15: 0000200000000680 CPU: 1 PID: 4266 Comm: syz-executor325 Not tainted 6.1.141-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 de d0 49 f7 48 89 df e8 36 96 4a f7 e8 31 97 6d f7 fb bf 01 00 00 00 46 13 3e f7 65 8b 05 17 d4 e8 75 85 c0 74 02 5b c3 e8 64 e5 e6 RSP: 0018:ffffc90003d27b50 EFLAGS: 00000282 RAX: 5f8f486fb0104400 RBX: ffff88802f15dc80 RCX: 5f8f486fb0104400 RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: 0000000000000001 RBP: ffffc90003d27cb0 R08: dffffc0000000000 R09: ffffed1005e2bb91 R10: ffffed1005e2bb91 R11: 1ffff11005e2bb90 R12: dffffc0000000000 R13: 0000000100000000 R14: 0000000000000000 R15: 0000000000000020 FS: 00007fb6affa36c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb6affa2e40 CR3: 000000007f15c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: set_current_blocked kernel/signal.c:3044 [inline] signal_delivered kernel/signal.c:2907 [inline] signal_setup_done+0x28c/0x440 kernel/signal.c:2919 handle_signal arch/x86/kernel/signal.c:846 [inline] arch_do_signal_or_restart+0xeba/0x1230 arch/x86/kernel/signal.c:873 exit_to_user_mode_loop+0x70/0x110 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+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb6b00085d0 Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 5a 20 03 00 e8 05 11 fb ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48 RSP: 002b:00007fb6affa2c78 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fb6b006c308 RCX: 00007fb6affe2699 RDX: 00007fb6affa2c80 RSI: 00007fb6affa2db0 RDI: 0000000000000021 RBP: 00007fb6b006c300 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000140 R13: 000020000006b000 R14: 0000200000000100 R15: 0000200000000680