rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=d7fc/1/0x4000000000000000 softirq=41605/41618 fqs=0 rcu: (detected by 1, t=10502 jiffies, g=38209, q=122 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12128 Comm: syz.2.1950 Not tainted 6.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:65 Code: c6 e0 b2 d1 8b 48 c7 c7 20 b3 d1 8b e9 f9 fe ff ff 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 89 fe 48 c7 c7 60 b3 d1 8b e9 cd fe ff ff 66 2e 0f RSP: 0018:ffffc90000007bf8 EFLAGS: 00000096 RAX: 0000000000000001 RBX: 1ffff92000000f81 RCX: ffffffff8175c37e RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffffff8b6cdaa0 RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff2dca598 R10: ffffffff96e52cc7 R11: 0000000000000002 R12: 0000000000000000 R13: ffffffff9aa4c550 R14: 0000000000000000 R15: 0000000000000000 FS: 00007ff1acc4c6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f511ff8 CR3: 00000000780a0000 CR4: 00000000003526f0 DR0: 0000000000002800 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_acquire.part.0+0x12b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 debug_object_activate+0x149/0x4a0 lib/debugobjects.c:818 debug_hrtimer_activate kernel/time/hrtimer.c:428 [inline] debug_activate kernel/time/hrtimer.c:469 [inline] enqueue_hrtimer+0x25/0x3c0 kernel/time/hrtimer.c:1076 __run_hrtimer kernel/time/hrtimer.c:1756 [inline] __hrtimer_run_queues+0x903/0xae0 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 06 64 4a f6 48 89 df e8 4e e3 4a f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 d5 d7 3b f6 65 8b 05 c6 91 d7 74 85 c0 74 16 5b RSP: 0018:ffffc9000364f818 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff888024dad140 RCX: 1ffffffff2dd3b47 RDX: 0000000000000000 RSI: ffffffff8b6cd7a0 RDI: ffffffff8bd1b360 RBP: 0000000000000282 R08: 0000000000000001 R09: fffffbfff2dca5af R10: ffffffff96e52d7f R11: 0000000000000004 R12: 0000000000000002 R13: ffff888024dad180 R14: ffff888024dacb28 R15: ffff888024dacfa8 __unix_dgram_recvmsg+0x32a/0xe50 net/unix/af_unix.c:2462 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2537 sock_recvmsg_nosec net/socket.c:1033 [inline] ____sys_recvmsg+0x5f8/0x6b0 net/socket.c:2801 ___sys_recvmsg+0x115/0x1a0 net/socket.c:2845 do_recvmmsg+0x2f8/0x740 net/socket.c:2940 __sys_recvmmsg net/socket.c:3014 [inline] __do_sys_recvmmsg net/socket.c:3037 [inline] __se_sys_recvmmsg net/socket.c:3030 [inline] __x64_sys_recvmmsg+0x239/0x290 net/socket.c:3030 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff1abd80849 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:00007ff1acc4c058 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007ff1abf46080 RCX: 00007ff1abd80849 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000004 RBP: 00007ff1abdf3986 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff1abf46080 R15: 00007ffc592b4db8 rcu: rcu_preempt kthread starved for 10502 jiffies! g38209 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:27600 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 d8 f4 d9 74 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 48 66 b3 00 fb f4 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d58 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8b29c759 RDX: 0000000000000001 RSI: ffff888143ae2000 RDI: ffff888143ae2064 RBP: ffff888143ae2064 R08: 0000000000000001 R09: ffffed10170e6fed R10: ffff8880b8737f6b R11: 0000000000000000 R12: ffff88801cfdd800 R13: ffffffff8ee14960 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555585b4b808 CR3: 0000000034b26000 CR4: 00000000003526f0 DR0: 0000000000002800 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:699 cpuidle_enter_state+0xaa/0x4f0 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:389 cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x310/0x3f0 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x222/0x2b0 arch/x86/kernel/smpboot.c:314 common_startup_64+0x13e/0x148