rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10089/1:b..l P4678/1:b..l rcu: (detected by 1, t=10503 jiffies, g=22469, q=608 ncpus=2) task:udevd state:R running task stack:21664 pid:4678 tgid:4678 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6997 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d e4 0b 9d 0c 48 89 de 5b e9 f3 c8 5d 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 c0 d7 03 00 65 8b 15 40 01 6f 7e 81 e2 00 01 ff 00 RSP: 0018:ffffc9000490f510 EFLAGS: 00000202 RAX: ffffffff820b55c3 RBX: ffffea00015fdb80 RCX: ffff88807d64da00 RDX: ffff88807d64da00 RSI: ffffffff8c60f900 RDI: ffffffff8c60f8c0 RBP: 0000000000000001 R08: ffffffff820b55b1 R09: 1ffffffff2858b00 R10: dffffc0000000000 R11: fffffbfff2858b01 R12: 0000000000000000 R13: ffffea00015fdb88 R14: ffffffff820b5580 R15: 1ffffd40002bfb70 rcu_read_lock include/linux/rcupdate.h:850 [inline] page_ext_get+0x63/0x2a0 mm/page_ext.c:525 __reset_page_owner+0x30/0x430 mm/page_owner.c:290 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2677 [inline] __put_partials+0xeb/0x130 mm/slub.c:3145 put_cpu_partial+0x17c/0x250 mm/slub.c:3220 __slab_free+0x2ea/0x3d0 mm/slub.c:4449 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x23/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:257 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4276 kmalloc_noprof include/linux/slab.h:882 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822 security_inode_getattr+0x130/0x330 security/security.c:2371 vfs_getattr+0x45/0x430 fs/stat.c:204 vfs_statx_path fs/stat.c:251 [inline] vfs_statx+0x199/0x490 fs/stat.c:315 vfs_fstatat+0x145/0x190 fs/stat.c:341 __do_sys_newfstatat fs/stat.c:505 [inline] __se_sys_newfstatat fs/stat.c:499 [inline] __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499 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: 0033:0x7fb4e11165f4 RSP: 002b:00007ffec52e1628 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000055e3655b51af RCX: 00007fb4e11165f4 RDX: 00007ffec52e1638 RSI: 00007ffec52e1ac8 RDI: 00000000ffffff9c RBP: 00007ffec52e16c8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffec52e1ac8 R13: 00007ffec52e1638 R14: 000055e398747910 R15: 0000000000000000 task:syz.2.2052 state:R running task stack:23824 pid:10089 tgid:10088 ppid:5228 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6854 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6878 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 unwind_next_frame+0x18f8/0x22d0 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2677 [inline] __put_partials+0xeb/0x130 mm/slub.c:3145 put_cpu_partial+0x17c/0x250 mm/slub.c:3220 __slab_free+0x2ea/0x3d0 mm/slub.c:4449 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 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 skb_clone+0x20c/0x390 net/core/skbuff.c:2084 do_one_broadcast net/netlink/af_netlink.c:1462 [inline] netlink_broadcast_filtered+0x707/0x12a0 net/netlink/af_netlink.c:1540 netlink_broadcast+0x39/0x50 net/netlink/af_netlink.c:1564 uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline] kobject_uevent_net_broadcast+0x38f/0x580 lib/kobject_uevent.c:410 kobject_uevent_env+0x57d/0x8e0 lib/kobject_uevent.c:608 device_remove drivers/base/dd.c:567 [inline] __device_release_driver drivers/base/dd.c:1273 [inline] device_release_driver_internal+0x4ab/0x7c0 drivers/base/dd.c:1296 driver_detach+0x1fb/0x2d0 drivers/base/dd.c:1359 bus_remove_driver+0x1f3/0x320 drivers/base/bus.c:744 usb_gadget_unregister_driver+0x4e/0x70 drivers/usb/gadget/udc/core.c:1731 raw_release+0xf6/0x1e0 drivers/usb/gadget/legacy/raw_gadget.c:462 __fput+0x241/0x880 fs/file_table.c:431 task_work_run+0x251/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f622af7dbfb RSP: 002b:00007f622bca3f10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007f622af7dbfb RDX: 00007f622bca4fe0 RSI: 0000000080085502 RDI: 0000000000000003 RBP: 00007f622bca4fe0 R08: 0000000000000080 R09: 00007f622bca3fd8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502 R13: 0000000800000000 R14: 0000000000000008 R15: 00007f622affa273 rcu: rcu_preempt kthread starved for 10592 jiffies! g22469 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:25912 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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: 5299 Comm: kworker/1:5 Not tainted 6.12.0-rc1-syzkaller-00330-gfc20a3e57247 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:trace_netif_rx_entry+0x87/0x210 Code: 92 c3 bf 02 00 00 00 89 de e8 b5 72 02 f8 31 ff 89 de e8 ac 72 02 f8 40 84 ed 74 10 e8 62 5e e8 f7 84 c0 74 0e e8 99 6f 02 f8 15 e8 92 6f 02 f8 eb 0e 80 3d d7 50 74 06 01 75 19 e8 82 6f 02 RSP: 0018:ffffc90000a172f0 EFLAGS: 00000246 RAX: ffffffff899266d7 RBX: 0000000000000001 RCX: ffff888024dd3c00 RDX: 0000000000000100 RSI: ffffffff8c60f900 RDI: ffffffff8c60f8c0 RBP: 0000000000000001 R08: ffffffff899266c4 R09: 1ffffffff2039d55 R10: dffffc0000000000 R11: fffffbfff2039d56 R12: ffff88805d047000 R13: ffff88805d0e2000 R14: 0000000000000000 R15: ffff88817c061b40 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2cc203 CR3: 000000000e734000 CR4: 0000000000350ef0 Call Trace: __netif_rx+0x70/0xc0 net/core/dev.c:5214 veth_forward_skb drivers/net/veth.c:322 [inline] veth_xmit+0x61d/0xae0 drivers/net/veth.c:375 __netdev_start_xmit include/linux/netdevice.h:4916 [inline] netdev_start_xmit include/linux/netdevice.h:4925 [inline] xmit_one net/core/dev.c:3588 [inline] dev_hard_start_xmit+0x27c/0x7e0 net/core/dev.c:3604 __dev_queue_xmit+0x1b11/0x3ed0 net/core/dev.c:4428 dev_queue_xmit include/linux/netdevice.h:3094 [inline] br_dev_queue_push_xmit+0x703/0x8d0 net/bridge/br_forward.c:53 NF_HOOK+0x702/0x7c0 include/linux/netfilter.h:314 br_nf_post_routing+0xa20/0xe80 net/bridge/br_netfilter_hooks.c:989 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x2a7/0x460 include/linux/netfilter.h:312 br_forward_finish+0xd8/0x130 net/bridge/br_forward.c:66 br_nf_forward_finish+0xb49/0xfb0 net/bridge/br_netfilter_hooks.c:689 NF_HOOK+0x702/0x7c0 include/linux/netfilter.h:314 br_nf_forward_ip+0x61e/0x7b0 net/bridge/br_netfilter_hooks.c:743 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x2a7/0x460 include/linux/netfilter.h:312 __br_forward+0x489/0x660 net/bridge/br_forward.c:115 br_handle_frame_finish+0x18ba/0x1fe0 net/bridge/br_input.c:215 br_nf_hook_thresh+0x474/0x590 br_nf_pre_routing_finish_ipv6+0xaa0/0xdd0 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x379/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x9ff/0x1530 net/bridge/br_input.c:424 __netif_receive_skb_core+0x13ea/0x4570 net/core/dev.c:5560 __netif_receive_skb_one_core net/core/dev.c:5664 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5779 process_backlog+0x662/0x15b0 net/core/dev.c:6111 __napi_poll+0xcd/0x490 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6966 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x75d/0xaa0 drivers/net/netdevsim/dev.c:850 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244