rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9964/2:b..l rcu: (detected by 0, t=10503 jiffies, g=32049, q=1014307 ncpus=2) task:syz.3.1067 state:R running task stack:26888 pid:9964 tgid:9960 ppid:5828 task_flags:0x40044c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_release+0xaf/0x3e0 kernel/locking/lockdep.c:5888 Code: 0a 00 00 00 0f 85 1e 02 00 00 49 81 3e 40 63 5d 93 0f 84 11 02 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 48 8b 5c 24 20 48 c7 c7 e6 10 98 8d e8 d4 bd c0 09 65 ff 05 cd aa fb 10 c7 44 RSP: 0018:ffffc9001111f0c8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000202 RCX: 5ae37eecc184e400 RDX: 0000000000000000 RSI: ffffffff8be1af20 RDI: ffffffff8be1aee0 RBP: 0000000000000001 R08: ffffea0001136f37 R09: 1ffffd4000226de6 R10: dffffc0000000000 R11: fffff94000226de7 R12: dffffc0000000000 R13: ffffffff81f78edc R14: ffffffff8e13eda0 R15: ffff888030de8000 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] page_ref_add_unless include/linux/page_ref.h:239 [inline] folio_ref_add_unless include/linux/page_ref.h:248 [inline] folio_try_get+0x1d1/0x340 include/linux/page_ref.h:264 find_get_entry mm/filemap.c:2050 [inline] find_lock_entries+0x24f/0xa60 mm/filemap.c:2140 shmem_undo_range+0x254/0x14b0 mm/shmem.c:1107 shmem_truncate_range mm/shmem.c:1237 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1365 evict+0x501/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:473 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6ad/0x22e0 kernel/exit.c:955 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 get_signal+0x125e/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd9ebf8e929 RSP: 002b:00007fd9e9df6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002b RAX: fffffffffffffe00 RBX: 00007fd9ec1b6160 RCX: 00007fd9ebf8e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007fd9ec010b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fd9ec1b6160 R15: 00007ffe62b166e8 rcu: rcu_preempt kthread starved for 445 jiffies! g32049 f0x2 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:27176 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 7412 Comm: kworker/u8:14 Not tainted 6.16.0-rc1-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 fb 7d 66 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 f3 69 2f f6 65 8b 05 ec 43 38 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90000007060 EFLAGS: 00000206 RAX: 4003e1a15f110800 RBX: 0000000000000a06 RCX: 4003e1a15f110800 RDX: 0000000000000002 RSI: ffffffff8d96d7bc RDI: 0000000000000001 RBP: ffffc900000070e0 R08: ffffffff8f9fdef7 R09: 1ffffffff1f3fbde R10: dffffc0000000000 R11: fffffbfff1f3fbdf R12: dffffc0000000000 R13: ffff888037124c80 R14: ffffffff99cabb80 R15: 1ffff92000000e0c FS: 0000000000000000(0000) GS:ffff888125c86000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff87b200000 CR3: 00000000770d6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:1108 [inline] debug_check_no_obj_freed+0x451/0x470 lib/debugobjects.c:1129 slab_free_hook mm/slub.c:2312 [inline] slab_free mm/slub.c:4643 [inline] kmem_cache_free+0x113/0x400 mm/slub.c:4745 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 nft_synproxy_eval_v4+0x376/0x560 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:272 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:315 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:317 __netif_receive_skb_one_core net/core/dev.c:5977 [inline] __netif_receive_skb+0x143/0x380 net/core/dev.c:6090 process_backlog+0x60e/0x14f0 net/core/dev.c:6442 __napi_poll+0xc4/0x480 net/core/dev.c:7414 napi_poll net/core/dev.c:7478 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7605 handle_softirqs+0x286/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] cfg80211_inform_single_bss_data+0x13d2/0x1ac0 net/wireless/scan.c:2383 cfg80211_inform_bss_data+0x1fb/0x3b20 net/wireless/scan.c:3222 cfg80211_inform_bss_frame_data+0x417/0x7b0 net/wireless/scan.c:3313 ieee80211_bss_info_update+0x746/0x9e0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1573 [inline] ieee80211_ibss_rx_queued_mgmt+0xa36/0x2ae0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1668 [inline] ieee80211_iface_work+0x806/0xfe0 net/mac80211/iface.c:1722 cfg80211_wiphy_work+0x2dc/0x460 net/wireless/core.c:435 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245