rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6916/1:b..l rcu: (detected by 0, t=10503 jiffies, g=18941, q=1077976 ncpus=2) task:syz.0.281 state:R running task stack:27960 pid:6916 tgid:6908 ppid:5614 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 56 5b 5c 00 48 89 df 5b e9 7d e6 61 00 be 03 00 00 00 5b e9 42 b4 f0 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 8b 05 05 e1 01 12 48 8b 34 24 65 48 8b 15 e1 e0 01 RSP: 0018:ffffc90003437800 EFLAGS: 00000287 RAX: 0000000000005db2 RBX: 0000000000000000 RCX: ffffc90010081000 RDX: 0000000000080000 RSI: ffffffff81cf10bb RDI: ffff888029ee8000 RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000008 R13: ffff88813fe5b000 R14: ffff88806bae4a30 R15: ffff888055a50840 queue_work_on+0x141/0x1e0 kernel/workqueue.c:2437 queue_work include/linux/workqueue.h:696 [inline] schedule_work include/linux/workqueue.h:757 [inline] __rhashtable_remove_fast_one include/linux/rhashtable.h:1118 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1142 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1171 [inline] simple_xattr_set+0x221a/0x36a0 fs/xattr.c:1399 shmem_xattr_handler_set+0x11c/0x400 mm/shmem.c:4337 __vfs_removexattr+0x155/0x1c0 fs/xattr.c:536 __vfs_removexattr_locked+0x107/0x4d0 fs/xattr.c:571 vfs_removexattr+0xe9/0x2b0 fs/xattr.c:593 ovl_do_removexattr fs/overlayfs/overlayfs.h:341 [inline] ovl_removexattr fs/overlayfs/overlayfs.h:349 [inline] ovl_make_workdir fs/overlayfs/super.c:756 [inline] ovl_get_workdir fs/overlayfs/super.c:836 [inline] ovl_fill_super_creds fs/overlayfs/super.c:1449 [inline] ovl_fill_super+0x1429/0x5e30 fs/overlayfs/super.c:1560 vfs_get_super fs/super.c:1327 [inline] get_tree_nodev+0xdd/0x190 fs/super.c:1346 vfs_get_tree+0x92/0x320 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount fs/namespace.c:3834 [inline] path_mount+0x7d0/0x23d0 fs/namespace.c:4154 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount fs/namespace.c:4360 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2e8939cdd9 RSP: 002b:00007f2e8a2f3028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f2e89616090 RCX: 00007f2e8939cdd9 RDX: 0000200000000000 RSI: 0000200000000100 RDI: 0000000000000000 RBP: 00007f2e89432d69 R08: 00002000000000c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2e89616128 R14: 00007f2e89616090 R15: 00007fff6b26fc38 rcu: rcu_preempt kthread starved for 427 jiffies! g18941 f0x2 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7282 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 421 Comm: kworker/u8:6 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__raw_spin_trylock include/linux/spinlock_api_smp.h:91 [inline] RIP: 0010:_raw_spin_trylock+0x3f/0x80 kernel/locking/spinlock.c:142 Code: ef e8 c5 36 58 f6 85 c0 75 20 89 c3 bf 01 00 00 00 e8 c5 0b 48 f6 65 8b 05 1e e1 7d 08 85 c0 74 37 89 d8 5b 5d e9 01 4c 00 00 74 24 10 48 8d 7d 18 ba 01 00 00 00 45 31 c9 bb 01 00 00 00 41 RSP: 0018:ffffc90000a081d8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffffc90000a082b0 RCX: ffffffff81e4c66e RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88813fe479d0 RBP: ffff88813fe479c0 R08: 0000000000000001 R09: fffff5200014102f R10: 0000000000000003 R11: 0000000000000000 R12: ffff88813fe479c0 R13: ffff88813fe4c8c0 R14: ffff888026832500 R15: 0000000000000028 FS: 0000000000000000(0000) GS:ffff888124479000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000003c6030 CR3: 000000005f8c2000 CR4: 00000000003526f0 Call Trace: _raw_spin_trylock_irqsave include/linux/spinlock_api_smp.h:112 [inline] _spin_trylock_irqsave include/linux/spinlock.h:426 [inline] get_from_partial_node+0x271/0x5a0 mm/slub.c:3797 get_from_partial mm/slub.c:3924 [inline] ___slab_alloc+0x88/0x8b0 mm/slub.c:4440 __slab_alloc_node mm/slub.c:4510 [inline] slab_alloc_node mm/slub.c:4886 [inline] kmem_cache_alloc_noprof+0x360/0x6e0 mm/slub.c:4905 kmem_alloc_batch+0x49/0x170 lib/debugobjects.c:371 fill_pool lib/debugobjects.c:420 [inline] debug_objects_fill_pool lib/debugobjects.c:742 [inline] debug_objects_fill_pool+0x24d/0x5a0 lib/debugobjects.c:714 debug_object_activate+0x103/0x490 lib/debugobjects.c:831 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline] __call_rcu_common.constprop.0+0x35/0x9b0 kernel/rcu/tree.c:3116 call_rcu_hurry include/linux/rcupdate.h:125 [inline] dst_release net/core/dst.c:178 [inline] dst_release+0x259/0x330 net/core/dst.c:166 refdst_drop include/net/dst.h:272 [inline] skb_dst_drop include/net/dst.h:284 [inline] skb_release_head_state+0x293/0x400 net/core/skbuff.c:1163 skb_release_all net/core/skbuff.c:1187 [inline] __kfree_skb net/core/skbuff.c:1203 [inline] consume_skb net/core/skbuff.c:1436 [inline] consume_skb+0x8a/0x110 net/core/skbuff.c:1430 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:61 [inline] nft_synproxy_do_eval+0xa72/0xd50 net/netfilter/nft_synproxy.c:142 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e5/0x1950 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] ip_local_deliver+0x163/0x1f0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:480 [inline] ip_rcv_finish net/ipv4/ip_input.c:492 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_rcv+0x33a/0x3c0 net/ipv4/ip_input.c:612 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6202 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6315 process_backlog+0x37a/0x1580 net/core/dev.c:6666 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7730 napi_poll net/core/dev.c:7793 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7950 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] cfg80211_put_bss+0x1b4/0x280 net/wireless/scan.c:3346 ieee80211_rx_bss_put net/mac80211/scan.c:37 [inline] ieee80211_rx_bss_put+0x43/0x60 net/mac80211/scan.c:32 ieee80211_rx_bss_info net/mac80211/ibss.c:1160 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1569 [inline] ieee80211_ibss_rx_queued_mgmt+0x1a3b/0x2f80 net/mac80211/ibss.c:1596 ieee80211_iface_process_skb net/mac80211/iface.c:1795 [inline] ieee80211_iface_work+0xbff/0x13e0 net/mac80211/iface.c:1849 cfg80211_wiphy_work+0x410/0x570 net/wireless/core.c:513 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245