rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9683/1:b..l rcu: (detected by 0, t=10503 jiffies, g=31861, q=115152 ncpus=2) task:syz.3.1932 state:R running task stack:27888 pid:9683 tgid:9678 ppid:6995 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1843/0x4ae0 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:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5829 Code: 2b 00 74 08 4c 89 f7 e8 da 1e 8b 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90019da7780 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920033b4efc RCX: 4f425956b94aab00 RDX: dffffc0000000000 RSI: ffffffff8c0adc40 RDI: ffffffff8c602d20 RBP: ffffc90019da78d8 R08: ffffffff94293807 R09: 1ffffffff2852700 R10: dffffc0000000000 R11: fffffbfff2852701 R12: 1ffff920033b4ef8 R13: dffffc0000000000 R14: ffffc90019da77e0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 __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+0xce4/0xf00 mm/page_alloc.c:2638 __slab_free+0x31b/0x3d0 mm/slub.c:4490 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x23/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:257 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4276 kmalloc_noprof include/linux/slab.h:882 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x23a/0x880 security/tomoyo/file.c:723 security_file_ioctl+0xc6/0x2a0 security/security.c:2910 __do_sys_ioctl fs/ioctl.c:901 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:893 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: 0033:0x7f53fd57dbfb RSP: 002b:00007f53fe338060 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f53fd57dbfb RDX: 0000000000000000 RSI: 0000000000006364 RDI: 00000000000000d9 RBP: 00007f53fd736058 R08: 0000000000000000 R09: 00007fff8e7b3307 R10: 0000000000000008 R11: 0000000000000246 R12: 00007f53fd736064 R13: 0000000000000001 R14: 00007fff8e7b3220 R15: 00007fff8e7b3308 rcu: rcu_preempt kthread starved for 10509 jiffies! g31861 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:26144 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1843/0x4ae0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5302 Comm: kworker/1:6 Not tainted 6.12.0-rc3-syzkaller-00087-gc964ced77262 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:314 Code: 44 0a 20 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 <65> 48 8b 14 25 80 d7 03 00 65 8b 05 30 ec 6e 7e 25 00 01 ff 00 74 RSP: 0018:ffffc90000a17bd8 EFLAGS: 00000282 RAX: 0000000000000100 RBX: 00000000fffffffe RCX: dffffc0000000000 RDX: ffff888025490000 RSI: 00000000fffffffe RDI: 00000000fffffffb RBP: ffffc90000a17dc8 R08: ffffffff8a776176 R09: 0000000000000000 R10: ffffc90000a17d30 R11: fffff52000142faa R12: ffff888060d91380 R13: ffff888060d91448 R14: ffff888060d91430 R15: ffffffff901d8fd0 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe805626922 CR3: 000000005e2d2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip6t_do_table+0x1106/0x18a0 net/ipv6/netfilter/ip6_tables.c:339 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook+0x2c4/0x450 include/linux/netfilter.h:269 NF_HOOK_COND include/linux/netfilter.h:302 [inline] ip6_output+0x26f/0x3c0 net/ipv6/ip6_output.c:247 synproxy_send_tcp_ipv6+0x568/0x7c0 net/netfilter/nf_synproxy_core.c:851 synproxy_send_client_synack_ipv6+0x7d0/0xc30 net/netfilter/nf_synproxy_core.c:897 nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:90 [inline] nft_synproxy_do_eval+0x739/0xa60 net/netfilter/nft_synproxy.c:145 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+0x1ea/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