rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7901/1:b..l rcu: (detected by 1, t=10502 jiffies, g=45905, q=638 ncpus=2) task:syz-executor state:R running task stack:21088 pid:7901 tgid:7901 ppid:7876 flags:0x20000000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6674 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6996 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:__nr_to_section include/linux/mmzone.h:1881 [inline] RIP: 0010:__pfn_to_section include/linux/mmzone.h:1989 [inline] RIP: 0010:lookup_page_ext mm/page_ext.c:251 [inline] RIP: 0010:page_ext_get+0x138/0x2a0 mm/page_ext.c:526 Code: 40 9a e8 9b 31 f3 ff 48 8b 05 44 bc 35 18 48 85 c0 74 41 4c 89 e1 48 c1 e9 16 48 8d 1c c8 48 89 d8 48 c1 e8 03 42 80 3c 38 00 <74> 08 48 89 df e8 6e 31 f3 ff 48 8b 1b 48 85 db 74 1f 4c 89 e5 48 RSP: 0018:ffffc9000310f3f8 EFLAGS: 00000246 RAX: 1ffff11047ffdea8 RBX: ffff88823ffef540 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000001cc22c0 RDI: 000000ffffffffc0 RBP: 000000ffffffffc0 R08: ffffffff820b3bee R09: 1ffffffff284b2f8 R10: dffffc0000000000 R11: fffffbfff284b2f9 R12: 000000000007308b R13: ffffea0001cc22c8 R14: ffffffff820b3b20 R15: dffffc0000000000 __page_table_check_zero+0xb1/0x350 mm/page_table_check.c:148 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1109 [inline] free_unref_page+0xd0f/0xf20 mm/page_alloc.c:2638 vfree+0x186/0x2e0 mm/vmalloc.c:3361 xt_compat_flush_offsets+0x77/0xb0 net/netfilter/x_tables.c:691 compat_do_ebt_get_ctl net/bridge/netfilter/ebtables.c:2438 [inline] do_ebt_get_ctl+0x10e3/0x29f0 net/bridge/netfilter/ebtables.c:2460 nf_getsockopt+0x299/0x2c0 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x222/0x2e0 net/ipv4/ip_sockglue.c:1777 tcp_getsockopt+0x163/0x1c0 net/ipv4/tcp.c:4670 do_sock_getsockopt+0x3c4/0x7e0 net/socket.c:2392 __sys_getsockopt+0x26b/0x330 net/socket.c:2421 __do_compat_sys_socketcall net/compat.c:494 [inline] __se_compat_sys_socketcall+0x349/0x1430 net/compat.c:423 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf73cd579 RSP: 002b:00000000f751f690 EFLAGS: 00000206 ORIG_RAX: 0000000000000066 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 00000000f751f6c8 RDX: 00000000f751f74c RSI: 00000000f751f750 RDI: 00000000f73bbff4 RBP: 00000000f751f750 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10411 jiffies! g45905 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:22224 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:6674 __schedule_loop kernel/sched/core.c:6751 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6766 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: CPU: 1 UID: 0 PID: 5311 Comm: kworker/1:8 Not tainted 6.11.0-syzkaller-08833-gde5cb0dcb74c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline] RIP: 0010:unwind_next_frame+0x1817/0x22d0 arch/x86/kernel/unwind_orc.c:665 Code: 8d 7d 08 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 7d 2f bd 00 4c 8b 75 08 48 8d 5d 10 48 89 d8 48 c1 e8 03 42 80 3c 20 00 <74> 08 48 89 df e8 5f 2f bd 00 4d 39 fe 0f 87 b2 00 00 00 48 8b 03 RSP: 0018:ffffc90000a17a70 EFLAGS: 00000246 RAX: 1ffff92000142f6a RBX: ffffc90000a17b50 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffc90003c60000 RDI: ffffc90000a17b48 RBP: ffffc90000a17b40 R08: ffffc90003c67ed0 R09: 0000000000000000 R10: ffffc90000a17b90 R11: fffff52000142f74 R12: dffffc0000000000 R13: ffffc90000a17b40 R14: ffffc90003c60000 R15: ffffc90003c67ee0 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f72a1760 CR3: 000000004f56a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4187 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1322 [inline] synproxy_send_client_synack+0x1ba/0xf30 net/netfilter/nf_synproxy_core.c:460 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 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:5662 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcb/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 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