rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16145/1:b..l P16155/1:b..l rcu: (detected by 1, t=10502 jiffies, g=79765, q=307 ncpus=2) task:syz.5.2427 state:R running task stack:26224 pid:16155 tgid:16138 ppid:15182 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872 Code: e3 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 52 be ee 0e 0f 82 74 02 00 00 8b 35 ea ee ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 69 e3 18 12 0f 85 ad 02 00 00 48 83 c4 RSP: 0018:ffffc9000c5f7458 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 00000000484b655b RDX: 0000000000000000 RSI: ffffffff8daa9241 RDI: ffffffff8bf2b280 RBP: 0000000000000002 R08: 00000000b65b6539 R09: 000000009b65b653 R10: 0000000000000002 R11: ffff888025592ff0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x20b0 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6878 kfree_const+0x55/0x60 mm/util.c:46 kobject_cleanup lib/kobject.c:695 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x213/0x6f0 lib/kobject.c:737 netdev_queue_update_kobjects+0x4e5/0x710 net/core/net-sysfs.c:2073 remove_queue_kobjects net/core/net-sysfs.c:2170 [inline] netdev_unregister_kobject+0x168/0x540 net/core/net-sysfs.c:2325 unregister_netdevice_many_notify+0x151e/0x2590 net/core/dev.c:12431 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x8fc/0xab0 net/core/net_namespace.c:248 setup_net+0x1ff/0x3a0 net/core/net_namespace.c:462 copy_net_ns+0x351/0x7c0 net/core/net_namespace.c:581 create_new_namespaces+0x3ea/0xab0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x45b/0xa40 kernel/fork.c:3171 __do_sys_unshare kernel/fork.c:3242 [inline] __se_sys_unshare kernel/fork.c:3240 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3240 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f463b18f749 RSP: 002b:00007f4638b8f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f463b3e6360 RCX: 00007f463b18f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000042000000 RBP: 00007f463b213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f463b3e63f8 R14: 00007f463b3e6360 R15: 00007ffd60d19928 task:syz.4.2426 state:R running task stack:24136 pid:16145 tgid:16145 ppid:5823 task_flags:0x400640 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:mtree_range_walk+0x62/0xc00 lib/maple_tree.c:2551 Code: 00 00 48 8b 42 18 4c 8d 62 20 4c 89 e1 48 89 44 24 20 48 c1 e9 03 48 b8 00 00 00 00 00 fc ff df 80 3c 01 00 0f 85 91 0a 00 00 <48> 8b 42 20 48 8d 6a 28 48 89 e9 48 89 44 24 38 48 c1 e9 03 48 b8 RSP: 0018:ffffc9000c786c80 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff88807ca03600 RCX: 1ffff920018f0db3 RDX: ffffc9000c786d78 RSI: ffffffff8b6f8ed7 RDI: ffffc9000c786d78 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000002 R10: 0000000000000000 R11: ffff8880329a8b30 R12: ffffc9000c786d98 R13: ffffc9000c786e70 R14: ffffc9000c786d90 R15: 0000000000000002 mas_state_walk lib/maple_tree.c:3298 [inline] mt_find+0x4c5/0xa20 lib/maple_tree.c:6497 find_vma+0xbf/0x140 mm/mmap.c:906 gup_vma_lookup+0x24/0x220 mm/gup.c:1275 __get_user_pages+0x241/0x3590 mm/gup.c:1396 __get_user_pages_locked mm/gup.c:1692 [inline] get_dump_page+0x257/0x3d0 mm/gup.c:2192 dump_user_range+0x195/0xb70 fs/coredump.c:1366 elf_core_dump+0x29c3/0x3c10 fs/binfmt_elf.c:2111 coredump_write fs/coredump.c:1049 [inline] do_coredump fs/coredump.c:1126 [inline] vfs_coredump+0x2b85/0x55e0 fs/coredump.c:1200 get_signal+0x22e1/0x26d0 kernel/signal.c:3019 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x38a/0x8c0 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f9f41d8f751 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f9f41fe6090 RCX: 00007f9f41d8f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f9f41e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f9f41fe6128 R14: 00007f9f41fe6090 R15: 00007ffecc3caf58 rcu: rcu_preempt kthread starved for 10587 jiffies! g79765 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:28776 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 26 5f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 99 11 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 0000000004c2d961 RBX: 0000000000000000 RCX: ffffffff8b78c6d9 RDX: 0000000000000000 RSI: ffffffff8dacf2d0 RDI: ffffffff8bf2b280 RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000 R13: ffffffff8e097b40 R14: ffffffff9088cad0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881248f1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30314ff8 CR3: 00000000779ef000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3ef/0x4d0 init/main.c:1206 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148