rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=43d/1/0x4000000000000000 softirq=8378/8380 fqs=4 (t=10501 jiffies g=10061 q=140) rcu: rcu_preempt kthread starved for 10494 jiffies! g10061 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:26168 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 4438 Comm: syz.6.26 Not tainted 5.15.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__lock_acquire+0xd84/0x1ff0 kernel/locking/lockdep.c:4995 Code: 0d 00 00 83 3d 7c 1f 46 15 00 b8 01 00 00 00 75 0a 49 83 ff ff 0f 85 b8 08 00 00 89 44 24 2c 48 89 d8 48 c1 e8 03 80 3c 38 00 <74> 12 48 89 df e8 f2 7b 67 00 48 bf 00 00 00 00 00 fc ff df 4c 89 RSP: 0018:ffffc9000361f9c0 EFLAGS: 00000046 RAX: 1ffff11004a28c86 RBX: ffff888025146430 RCX: ffffffff96a8ef03 RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffff888025146420 R08: dffffc0000000000 R09: fffffbfff2131027 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: ffff888025146428 R14: 1ffff11004a28c84 R15: ffffffffffffffff FS: 0000555567f97500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 000000005a081000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __might_fault+0xb4/0x110 mm/memory.c:5355 _copy_from_user+0x28/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:192 [inline] restore_sigcontext+0xce/0x710 arch/x86/kernel/signal.c:91 __do_sys_rt_sigreturn+0x190/0x250 arch/x86/kernel/signal.c:674 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc434dd0129 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007ffcfa183d00 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007fc434ff9fa0 RCX: 00007fc434dd0129 RDX: 00007ffcfa183d00 RSI: 00007ffcfa183e30 RDI: 0000000000000011 RBP: 00007fc434ea7986 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc434ff9fa0 R14: 00007fc434ff9fa0 R15: 000000000000141a NMI backtrace for cpu 0 CPU: 0 PID: 4437 Comm: syz.1.29 Not tainted 5.15.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x320/0x600 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0x8d9/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 31 61 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 1e a5 1a f7 48 89 df e8 76 f9 1b f7 e8 31 b4 3e f7 fb bf 01 00 00 00 d6 3e 0f f7 65 8b 05 f7 31 ba 75 85 c0 74 02 5b c3 e8 c4 4e b8 RSP: 0018:ffffc9000362fbc0 EFLAGS: 00000282 RAX: 96405535ed2f1b00 RBX: ffff88805ec3c0c0 RCX: ffffffff96a8ef03 RDX: dffffc0000000000 RSI: ffffffff8aab2a80 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff8186f220 R09: ffffed100bd87819 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000011 R13: dffffc0000000000 R14: ffff88805ec3c358 R15: ffff88805ec3c0c0 spin_unlock_irq include/linux/spinlock.h:413 [inline] get_signal+0x13ee/0x14e0 kernel/signal.c:2903 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f765c8daf19 Code: 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 01 48 RSP: 002b:00007ffdc33cf2d8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f765caa0fa0 RCX: 00007f765c8daf19 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f765c94e986 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f765caa0fa0 R14: 00007f765caa0fa0 R15: 000000000000141a sched: RT throttling activated