rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5486/1:b..l P23004/1:b..l rcu: (detected by 1, t=10502 jiffies, g=127177, q=415 ncpus=2) task:syz-executor state:R running task stack:21672 pid:23004 tgid:23004 ppid:22989 task_flags:0x480140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x44/0x3e0 kernel/locking/lockdep.c:5879 Code: 8b 05 10 1d f4 10 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 13 1d f4 10 83 f8 08 0f 83 9a 02 00 00 89 c0 48 0f a3 05 3c 1e 01 0e <73> 16 e8 a5 ea 08 00 84 c0 75 0d f6 05 e9 29 eb 0d 01 0f 84 ad 02 RSP: 0018:ffffc90003a1ecd0 EFLAGS: 00000297 RAX: 0000000000000001 RBX: ffffffff90d2a701 RCX: ee43688702bc4e00 RDX: ffffc90003a1ee01 RSI: ffffffff81731d25 RDI: ffffffff8e13d320 RBP: dffffc0000000000 R08: ffffc90003a1ff38 R09: ffffc90003a1ee58 R10: dffffc0000000000 R11: fffff52000743dcd R12: ffffc90003a1ff48 R13: ffffffff81731d25 R14: ffffffff8e13d320 R15: ffffffff81731d25 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2515 [inline] slab_free mm/slub.c:6574 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6684 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1398 netlink_broadcast_filtered+0xec7/0x1000 net/netlink/af_netlink.c:1537 netlink_broadcast+0x37/0x50 net/netlink/af_netlink.c:1559 uevent_net_broadcast_tagged lib/kobject_uevent.c:373 [inline] kobject_uevent_net_broadcast+0x4bc/0x560 lib/kobject_uevent.c:413 kobject_uevent_env+0x55b/0x8c0 lib/kobject_uevent.c:608 device_del+0x73a/0x8e0 drivers/base/core.c:3896 unregister_netdevice_many_notify+0x1a6b/0x1ff0 net/core/dev.c:12289 unregister_netdevice_many net/core/dev.c:12317 [inline] unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:12161 unregister_netdevice include/linux/netdevice.h:3389 [inline] nsim_destroy+0x1dd/0x670 drivers/net/netdevsim/netdev.c:1171 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1473 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1485 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1707 nsim_drv_remove+0x58/0x160 drivers/net/netdevsim/dev.c:1722 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1274 [inline] device_release_driver_internal+0x46f/0x800 drivers/base/dd.c:1297 bus_remove_device+0x34d/0x410 drivers/base/bus.c:579 device_del+0x511/0x8e0 drivers/base/core.c:3878 device_unregister+0x20/0xc0 drivers/base/core.c:3919 nsim_bus_dev_del drivers/net/netdevsim/bus.c:483 [inline] del_device_store+0x2aa/0x360 drivers/net/netdevsim/bus.c:244 kernfs_fop_write_iter+0x3af/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f82fb78d97f RSP: 002b:00007ffff16a2280 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f82fb78d97f RDX: 0000000000000001 RSI: 00007ffff16a22d0 RDI: 0000000000000005 RBP: 00007f82fb813239 R08: 0000000000000000 R09: 00007ffff16a20d7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffff16a22d0 R14: 00007f82fc514620 R15: 0000000000000003 task:dhcpcd state:R running task stack:21288 pid:5486 tgid:5486 ppid:5485 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:kasan_byte_accessible+0x16/0x30 mm/kasan/generic.c:212 Code: 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df 0f b6 04 07 <3c> 08 0f 92 c0 e9 eb 14 eb fe cc 66 66 66 66 66 66 2e 0f 1f 84 00 RSP: 0018:ffffc900031b7040 EFLAGS: 00000212 RAX: 0000000000000000 RBX: ffffffff81aa34c9 RCX: 5fc42a44c2373e00 RDX: 0000000000000000 RSI: ffffffff81aa34c9 RDI: 1ffffffff1c27a64 RBP: ffffffff81aa34ad R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff81abbce0 R12: 0000000000000002 R13: ffffffff8e13d320 R14: ffffffff8e13d320 R15: 0000000000000000 __kasan_check_byte+0x12/0x40 mm/kasan/common.c:579 kasan_check_byte include/linux/kasan.h:401 [inline] lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5842 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] is_module_text_address+0x39/0x1e0 kernel/module/main.c:3845 kernel_text_address+0x94/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4947 [inline] slab_alloc_node mm/slub.c:5246 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5253 mt_alloc_one lib/maple_tree.c:172 [inline] mas_dup_build+0x141/0x1250 lib/maple_tree.c:6297 __mt_dup+0x147/0x230 lib/maple_tree.c:6380 dup_mmap+0x3be/0x1b10 mm/mmap.c:1745 dup_mm kernel/fork.c:1489 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1541 copy_process+0x1706/0x3c00 kernel/fork.c:2181 kernel_clone+0x21e/0x840 kernel/fork.c:2609 __do_sys_clone kernel/fork.c:2750 [inline] __se_sys_clone kernel/fork.c:2734 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f22d35fa636 RSP: 002b:00007ffd4e1f57e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd4e1f57e8 RCX: 00007f22d35fa636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd4e215d30 R08: 0000000000000000 R09: 0000000000000001 R10: 00007f22d3526a10 R11: 0000000000000246 R12: 00007ffd4e1f5920 R13: 0000000000000000 R14: 0000000000000000 R15: 000055d36794cac0 rcu: rcu_preempt kthread starved for 10559 jiffies! g127177 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:27352 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 2e e3 c4 f5 cc cc cc 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 e3 d0 1c 00 f3 0f 1e fa fb f4 03 e3 c4 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: 43165f6109da3500 RBX: ffffffff81960c17 RCX: 43165f6109da3500 RDX: 0000000000000001 RSI: ffffffff8d7e8a21 RDI: ffffffff8bc077e0 RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8f9e1170 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100385eb58 FS: 0000000000000000(0000) GS:ffff888125e0f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f32bda6d76f CR3: 0000000061566000 CR4: 0000000000350ef0 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+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147