rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14497/2:b..l rcu: (detected by 1, t=10503 jiffies, g=85901, q=832157 ncpus=2) task:syz.4.1942 state:R running task stack:23960 pid:14497 tgid:14496 ppid:14119 flags:0x00000000 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:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:__local_bh_enable_ip+0x170/0x200 kernel/softirq.c:389 Code: 8c e8 74 30 6e 0a 65 66 8b 05 e4 52 ac 7e 66 85 c0 75 5d bf 01 00 00 00 e8 bd ae 0b 00 e8 98 1a 45 00 fb 65 8b 05 a8 52 ac 7e <85> c0 75 05 e8 47 31 a9 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c RSP: 0018:ffffc90002f2ea00 EFLAGS: 00000286 RAX: 0000000000000000 RBX: 1ffff920005e5d44 RCX: ffffffff8170bc6a RDX: dffffc0000000000 RSI: ffffffff8c0acac0 RDI: ffffffff8c60f860 RBP: ffffc90002f2eab0 R08: ffffffff942c6897 R09: 1ffffffff2858d12 R10: dffffc0000000000 R11: fffffbfff2858d13 R12: dffffc0000000000 R13: 1ffff920005e5d48 R14: ffffc90002f2ea40 R15: 0000000000000200 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] __dev_queue_xmit+0x171d/0x3ed0 net/core/dev.c:4455 dev_queue_xmit include/linux/netdevice.h:3101 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 ip_local_out net/ipv4/ip_output.c:130 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:536 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:4059 [inline] tcp_connect+0x2c1d/0x4940 net/ipv4/tcp_output.c:4148 tcp_v4_connect+0x1127/0x1ba0 net/ipv4/tcp_ipv4.c:341 __inet_stream_connect+0x262/0xf30 net/ipv4/af_inet.c:679 tcp_sendmsg_fastopen+0x3a2/0x5d0 net/ipv4/tcp.c:1039 tcp_sendmsg_locked+0x48d2/0x4f30 net/ipv4/tcp.c:1091 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1358 smc_sendmsg+0x258/0x530 net/smc/af_smc.c:2786 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2602 ___sys_sendmsg net/socket.c:2656 [inline] __sys_sendmsg+0x292/0x380 net/socket.c:2685 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: 0033:0x7fb9e5b7dff9 RSP: 002b:00007fb9e6a16038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fb9e5d35f80 RCX: 00007fb9e5b7dff9 RDX: 000000002000488c RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00007fb9e5bf0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb9e5d35f80 R15: 00007ffc2964a7a8 rcu: rcu_preempt kthread starved for 2850 jiffies! g85901 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:25752 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+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5235 Comm: kworker/0:3 Not tainted 6.12.0-rc1-syzkaller-00360-g09cf85ef183a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:979 [inline] RIP: 0010:debug_check_no_obj_freed+0x2be/0x580 lib/debugobjects.c:1019 Code: ff c7 48 8b 44 24 38 48 85 c0 0f 84 a4 02 00 00 49 89 c4 49 89 c5 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 <74> 08 4c 89 e7 e8 98 2e 3c fd 49 8b 04 24 48 89 44 24 38 49 8d 5c RSP: 0018:ffffc90000006f00 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff8881906b8018 RCX: dffffc0000000000 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc90000006de0 RBP: ffffc90000007060 R08: 0000000000000003 R09: fffff52000000dbc R10: dffffc0000000000 R11: fffff52000000dbc R12: ffff8881906b8038 R13: 1ffff110320d7007 R14: ffff8881906bd550 R15: 000000000000003b FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f47b59fd8b8 CR3: 000000002795c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: slab_free_hook mm/slub.c:2274 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x11f/0x440 mm/slub.c:4728 skb_kfree_head net/core/skbuff.c:1086 [inline] skb_free_head net/core/skbuff.c:1098 [inline] skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1125 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] consume_skb+0x9f/0xf0 net/core/skbuff.c:1436 nft_synproxy_eval_v4+0x3d2/0x610 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5666 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5779 process_backlog+0x662/0x15b0 net/core/dev.c:6111 __napi_poll+0xcb/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+0x2c5/0x980 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+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244