rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5421/2:b..l P5381/1:b..l rcu: (detected by 1, t=10502 jiffies, g=6649, q=1071690 ncpus=2) task:syz.1.24 state:R running task stack:21464 pid:5381 tgid:5378 ppid:5230 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7004 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:stack_trace_consume_entry+0x46/0x280 kernel/stacktrace.c:86 Code: fc ff df 4c 8d 4f 10 4d 89 cf 49 c1 ef 03 41 0f b6 04 17 84 c0 0f 85 06 01 00 00 44 8b 43 10 48 8d 6b 08 49 89 ec 49 c1 ec 03 <41> 0f b6 04 14 84 c0 0f 85 1a 01 00 00 44 3b 45 00 73 3c 48 8d 7b RSP: 0018:ffffc900043f6d30 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffffc900043f6e60 RCX: ffffffff917bd000 RDX: dffffc0000000000 RSI: ffffffff81570217 RDI: ffffc900043f6e60 RBP: ffffc900043f6e68 R08: 000000000000000a R09: ffffc900043f6e70 R10: ffffc900043f6dd0 R11: ffffffff8180a0e0 R12: 1ffff9200087edcd R13: ffffffff8180a0e0 R14: ffffc900043f6e60 R15: 1ffff9200087edce arch_stack_walk+0x10e/0x150 arch/x86/kernel/stacktrace.c:27 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_folios+0xf12/0x18d0 mm/page_alloc.c:2686 folios_put_refs+0x76c/0x860 mm/swap.c:1007 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x64c/0x1cf0 mm/shmem.c:1032 shmem_truncate_range mm/shmem.c:1144 [inline] shmem_evict_inode+0x29b/0xa80 mm/shmem.c:1272 evict+0x4e8/0x9b0 fs/inode.c:725 __dentry_kill+0x20d/0x630 fs/dcache.c:615 dput+0x19f/0x2b0 fs/dcache.c:857 __fput+0x5d2/0x880 fs/file_table.c:439 task_work_run+0x24f/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: 0033:0x7f18e4b7dff9 RSP: 002b:00007f18e599b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f18e4d36060 RCX: 00007f18e4b7dff9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f18e4d36060 RBP: 00007f18e4d36058 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f18e4d36064 R13: 0000000000000000 R14: 00007fffb0076a40 R15: 00007fffb0076b28 task:syz.4.35 state:R running task stack:24264 pid:5421 tgid:5417 ppid:5238 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6861 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6885 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0x179/0x200 kernel/softirq.c:389 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:4457 dev_queue_xmit include/linux/netdevice.h:3122 [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:4056 [inline] tcp_connect+0x2c1d/0x4940 net/ipv4/tcp_output.c:4145 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 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:744 __sys_sendto+0x39b/0x4f0 net/socket.c:2214 __do_sys_sendto net/socket.c:2226 [inline] __se_sys_sendto net/socket.c:2222 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2222 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: 0033:0x7f2cc237dff9 RSP: 002b:00007f2cc31ec038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f2cc2536058 RCX: 00007f2cc237dff9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f2cc23f0296 R08: 0000000020e68000 R09: 0000000000000010 R10: 00000000200007fd R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2cc2536058 R15: 00007ffd8b2b74a8 rcu: rcu_preempt kthread starved for 10598 jiffies! g6649 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:25952 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 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: 5350 Comm: kworker/0:7 Not tainted 6.12.0-rc2-syzkaller-00543-g6aac56631831 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:deref_stack_reg+0x18f/0x210 arch/x86/kernel/unwind_orc.c:406 Code: 31 c0 4c 39 e1 76 33 4c 39 f9 77 2e 4c 89 c7 48 89 d3 e8 f4 07 00 00 49 89 c6 48 8b 6c 24 18 48 89 e8 48 c1 e8 03 80 3c 18 00 <74> 08 48 89 ef e8 27 0b bd 00 4c 89 75 00 b0 01 48 83 c4 20 5b 41 RSP: 0018:ffffc90000006498 EFLAGS: 00000246 RAX: 1ffff92000000cc0 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffc90000000000 RDI: ffffc90000006ef0 RBP: ffffc90000006600 R08: ffffc90000006ef0 R09: 0000000000000000 R10: ffffc90000006610 R11: fffff52000000cc4 R12: 1ffff92000000cb9 R13: 1ffff92000000cba R14: ffffc90000007040 R15: ffffc90000008000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f18e5979f98 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x1799/0x22d0 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 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kmem_cache_free+0x1a2/0x420 mm/slub.c:4681 packet_rcv+0x16f/0x14b0 net/packet/af_packet.c:2290 dev_queue_xmit_nit+0xad4/0xc10 net/core/dev.c:2347 xmit_one net/core/dev.c:3586 [inline] dev_hard_start_xmit+0x15f/0x7e0 net/core/dev.c:3606 __dev_queue_xmit+0x1b11/0x3ed0 net/core/dev.c:4430 dev_queue_xmit include/linux/netdevice.h:3122 [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 synproxy_send_client_synack+0x8b8/0xf30 net/netfilter/nf_synproxy_core.c:484 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:5668 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5781 process_backlog+0x662/0x15b0 net/core/dev.c:6113 __napi_poll+0xcb/0x490 net/core/dev.c:6777 napi_poll net/core/dev.c:6846 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6968 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