rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=726c/1/0x4000000000000000 softirq=106597/106604 fqs=7 rcu: (detected by 1, t=10502 jiffies, g=150417, q=510 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9431 Comm: kworker/u4:19 Not tainted 6.5.0-rc1-syzkaller-00259-g831fe284d827 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 Workqueue: netns cleanup_net RIP: 0010:do_raw_spin_lock+0x1f2/0x3a0 kernel/locking/spinlock_debug.c:118 Code: 04 02 00 00 00 00 65 48 8b 04 25 28 00 00 00 48 3b 84 24 80 00 00 00 0f 85 b2 01 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f <5d> c3 4c 89 e7 48 c7 c6 80 e6 0a 8b e8 bd 18 00 00 48 ba 00 00 00 RSP: 0018:ffffc90000007cb0 EFLAGS: 00000046 RAX: c274b0e4bd237f00 RBX: 1ffff92000000f9c RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc90000007c40 RBP: ffffc90000007cb0 R08: 0000000000000003 R09: fffff52000000f88 R10: dffffc0000000000 R11: fffff52000000f88 R12: ffff8880b982b740 R13: 1ffff92000000f98 R14: ffffc90000007ce0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff7e1ac56be CR3: 000000007d069000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irq include/linux/spinlock_api_smp.h:120 [inline] _raw_spin_lock_irq+0xdf/0x120 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x66c/0xd10 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x396/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1098 [inline] __sysvec_apic_timer_interrupt+0x13f/0x480 arch/x86/kernel/apic/apic.c:1115 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1109 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_is_held_type+0x13b/0x190 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90015db78b8 EFLAGS: 00000206 RAX: c274b0e4bd237f00 RBX: 0000000000000003 RCX: ffff88807380bb80 RDX: 0000000000000000 RSI: ffffffff8b0aa1c0 RDI: ffffffff8b58a4c0 RBP: 0000000000000000 R08: ffffffff8e9854ef R09: 1ffffffff1d30a9d R10: dffffc0000000000 R11: fffffbfff1d30a9e R12: 0000000000000246 R13: ffff88807380bb80 R14: 00000000ffffffff R15: ffffffff8d3288a0 lock_is_held include/linux/lockdep.h:288 [inline] __might_resched+0xf4/0x780 kernel/sched/core.c:10151 inet_twsk_purge+0x119/0xad0 net/ipv4/inet_timewait_sock.c:291 ops_exit_list net/core/net_namespace.c:175 [inline] cleanup_net+0x767/0xb80 net/core/net_namespace.c:614 process_one_work+0x92c/0x12c0 kernel/workqueue.c:2597 worker_thread+0xa63/0x1210 kernel/workqueue.c:2748 kthread+0x2b8/0x350 kernel/kthread.c:389 ret_from_fork+0x2e/0x60 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296 RIP: 0000:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10467 jiffies! g150417 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:25640 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1873/0x48f0 kernel/sched/core.c:6710 schedule+0xc3/0x180 kernel/sched/core.c:6786 schedule_timeout+0x1bd/0x310 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x2c6/0x1010 kernel/rcu/tree.c:1609 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1808 kthread+0x2b8/0x350 kernel/kthread.c:389 ret_from_fork+0x2e/0x60 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296 RIP: 0000:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 13211 Comm: syz-executor.4 Not tainted 6.5.0-rc1-syzkaller-00259-g831fe284d827 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 RIP: 0010:csd_lock_wait kernel/smp.c:296 [inline] RIP: 0010:smp_call_function_many_cond+0x1856/0x27d0 kernel/smp.c:835 Code: 03 84 c0 75 7e 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 5e 17 0b 00 41 83 e5 01 4c 8b 6c 24 60 75 07 e8 9e 13 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 04 24 RSP: 0018:ffffc900034ef540 EFLAGS: 00000293 RAX: ffffffff8180f027 RBX: 1ffff1101730897d RCX: ffff8880295cd940 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900034ef740 R08: ffffffff8180eff2 R09: 1ffffffff20f6266 R10: dffffc0000000000 R11: fffffbfff20f6267 R12: ffff8880b9844be8 R13: ffff8880b993d0c8 R14: ffff8880b993d0c0 R15: 0000000000000000 FS: 000055555616f480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000007d069000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1003 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline] flush_tlb_multi arch/x86/mm/tlb.c:943 [inline] flush_tlb_mm_range+0x332/0x530 arch/x86/mm/tlb.c:1029 dup_mmap kernel/fork.c:774 [inline] dup_mm kernel/fork.c:1689 [inline] copy_mm+0x180a/0x1ee0 kernel/fork.c:1738 copy_process+0x1a0f/0x4290 kernel/fork.c:2504 kernel_clone+0x222/0x800 kernel/fork.c:2912 __do_sys_clone kernel/fork.c:3055 [inline] __se_sys_clone kernel/fork.c:3039 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:3039 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7a56679b53 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd1a4e8818 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7a56679b53 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 000055555616f750 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001