rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=0084/1/0x4000000000000000 softirq=34484/34485 fqs=2 rcu: (detected by 0, t=10505 jiffies, g=33553, q=242 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10851 Comm: syz.5.1322 Not tainted 6.12.0-rc5-syzkaller-00044-gc1e939a21eb1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3816 [inline] RIP: 0010:validate_chain+0x119/0x5920 kernel/locking/lockdep.c:3872 Code: 25 00 80 04 00 3d 00 00 04 00 0f 85 80 04 00 00 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 00 68 29 94 be 08 00 00 00 02 77 8a 00 48 0f a3 1d ea 67 b8 12 72 66 48 c7 c0 40 d9 39 9a RSP: 0018:ffffc90000a18600 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 1ffff920001430e0 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff94296800 RBP: ffffc90000a18900 R08: ffffffff94296807 R09: 1ffffffff2852d00 R10: dffffc0000000000 R11: fffffbfff2852d01 R12: dffffc0000000000 R13: ffff8880304b4750 R14: 8f1279fecd576743 R15: ffff8880304b4750 FS: 00007f9eda9ff6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c319ef2 CR3: 000000002733e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 debug_object_activate+0x16d/0x510 lib/debugobjects.c:708 debug_hrtimer_activate kernel/time/hrtimer.c:423 [inline] debug_activate kernel/time/hrtimer.c:478 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1085 __run_hrtimer kernel/time/hrtimer.c:1708 [inline] __hrtimer_run_queues+0x6cb/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:stack_trace_consume_entry+0x135/0x280 kernel/stacktrace.c:95 Code: 4c 89 ee 4c 89 f2 48 89 33 41 8b 19 41 0f b6 04 14 84 c0 0f 85 34 01 00 00 3b 5d 00 0f 92 c0 48 83 c4 18 5b 41 5c 41 5d 41 5e <41> 5f 5d c3 cc cc cc cc 44 89 c9 80 e1 07 80 c1 03 38 c1 0f 8c e9 RSP: 0018:ffffc900192274a8 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffffc900192274c0 RCX: ffffffff9179e000 RDX: dffffc0000000000 RSI: ffffffff82368fa5 RDI: ffffc900192275ac RBP: ffffc900192275a8 R08: 0000000000000004 R09: ffffc900192275b0 R10: ffffc90019227510 R11: ffffffff81809220 R12: ffff8880304b3c00 R13: ffffffff81809220 R14: ffffc900192275a0 R15: 1ffff92003244eb6 arch_stack_walk+0x10e/0x150 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 __proc_create+0x44f/0xa50 fs/proc/generic.c:425 _proc_mkdir fs/proc/generic.c:489 [inline] proc_mkdir_data fs/proc/generic.c:506 [inline] proc_mkdir+0xa5/0x180 fs/proc/generic.c:520 create_cache_proc_entries net/sunrpc/cache.c:1677 [inline] cache_register_net+0x262/0x4c0 net/sunrpc/cache.c:1720 ip_map_cache_create+0x73/0xf0 net/sunrpc/svcauth_unix.c:1044 sunrpc_init_net+0x47/0x160 net/sunrpc/sunrpc_syms.c:42 ops_init+0x31e/0x590 net/core/net_namespace.c:139 setup_net+0x287/0x9e0 net/core/net_namespace.c:356 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:494 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228 ksys_unshare+0x57d/0xa70 kernel/fork.c:3311 __do_sys_unshare kernel/fork.c:3382 [inline] __se_sys_unshare kernel/fork.c:3380 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3380 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9edaf7e719 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:00007f9eda9ff038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f9edb135f80 RCX: 00007f9edaf7e719 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000068060200 RBP: 00007f9edaff132e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9edb135f80 R15: 00007ffe7c64c498 rcu: rcu_preempt kthread starved for 10495 jiffies! g33553 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:25680 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x185a/0x4b70 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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: 0 UID: 0 PID: 10857 Comm: syz.5.1322 Not tainted 6.12.0-rc5-syzkaller-00044-gc1e939a21eb1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f3/0x2ca0 kernel/smp.c:884 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 86 f3 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 31 ef 0b 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 15 ef RSP: 0018:ffffc9001925f2c0 EFLAGS: 00000246 RAX: ffffffff8188eaab RBX: 1ffff110170e8911 RCX: 0000000000040000 RDX: ffffc9000ca47000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc9001925f4c0 R08: ffffffff8188ea7a R09: 1ffffffff2852d06 R10: dffffc0000000000 R11: fffffbfff2852d07 R12: dffffc0000000000 R13: ffff8880b8744888 R14: ffff8880b863fc40 R15: 0000000000000001 FS: 00007f9eda9bd6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9eda9bcf98 CR3: 000000002733e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000cdb2 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:938 [inline] flush_tlb_mm_range+0x329/0x5c0 arch/x86/mm/tlb.c:1024 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:465 [inline] tlb_flush_mmu+0x1aa/0x680 mm/mmu_gather.c:372 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 vms_clear_ptes+0x437/0x530 mm/vma.c:1103 vms_clean_up_area+0x62/0x1c0 mm/vma.c:1115 mmap_region+0x1063/0x2940 mm/mmap.c:1427 do_mmap+0x8f0/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9edaf7e719 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:00007f9eda9bd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f9edb136130 RCX: 00007f9edaf7e719 RDX: 0000000003000002 RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007f9edaff132e R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9edb136130 R15: 00007ffe7c64c498