rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9614/1:b..l P4673/2:b..l rcu: (detected by 0, t=10502 jiffies, g=59753, q=2425599 ncpus=2) task:udevd state:R running task stack:21040 pid:4673 tgid:4673 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 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:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5826 Code: 2b 00 74 08 4c 89 f7 e8 da 2c 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:ffffc9000386f600 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200070decc RCX: bb3c0d7e12a9eb00 RDX: dffffc0000000000 RSI: ffffffff8c0adbc0 RDI: ffffffff8c6009c0 RBP: ffffc9000386f748 R08: ffffffff942257c7 R09: 1ffffffff2844af8 R10: dffffc0000000000 R11: fffffbfff2844af9 R12: 1ffff9200070dec8 R13: dffffc0000000000 R14: ffffc9000386f660 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] rhashtable_lookup_fast include/linux/rhashtable.h:671 [inline] __netlink_lookup+0xd7/0x890 net/netlink/af_netlink.c:516 netlink_lookup+0xda/0x200 net/netlink/af_netlink.c:536 netlink_getsockbyportid net/netlink/af_netlink.c:1168 [inline] netlink_unicast+0x1aa/0x990 net/netlink/af_netlink.c:1351 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2603 ___sys_sendmsg net/socket.c:2657 [inline] __sys_sendmsg+0x2aa/0x390 net/socket.c:2686 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: 0033:0x7f484e924a4b RSP: 002b:00007ffccbdb5ca8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000555e17eafdf0 RCX: 00007f484e924a4b RDX: 0000000000000000 RSI: 00007ffccbdb5cb8 RDI: 0000000000000004 RBP: 0000555e17ec0f10 R08: 0000000000000001 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000000b3 R14: 0000000000000000 R15: 0000000000000000 task:syz.3.1283 state:R running task stack:25696 pid:9614 tgid:9612 ppid:8191 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 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: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_cmp8+0x8/0x90 kernel/kcov.c:321 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 0c 25 80 d7 03 00 65 8b 05 30 19 6f 7e 25 00 01 ff 00 74 RSP: 0018:ffffc90004887118 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000043 RCX: ffff888025619e00 RDX: 0000000000000000 RSI: 0000000000000043 RDI: 0000000000000043 RBP: ffffc900048871d0 R08: ffffffff81e72680 R09: 1ffffffff2844af8 R10: dffffc0000000000 R11: fffffbfff2844af9 R12: 0000000000000000 R13: 000000006a999067 R14: dffffc0000000000 R15: 0000000000000000 pmd_bad arch/x86/include/asm/pgtable.h:1101 [inline] __pte_offset_map+0x2b0/0x380 mm/pgtable-generic.c:298 __pte_offset_map_lock+0xc7/0x300 mm/pgtable-generic.c:371 pte_offset_map_lock include/linux/mm.h:3014 [inline] zap_pte_range mm/memory.c:1600 [inline] zap_pmd_range mm/memory.c:1739 [inline] zap_pud_range mm/memory.c:1768 [inline] zap_p4d_range mm/memory.c:1789 [inline] unmap_page_range+0x9b5/0x40e0 mm/memory.c:1810 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1900 exit_mmap+0x275/0xc40 mm/mmap.c:1860 __mmput+0x115/0x380 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x28e0 kernel/exit.c:926 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x176f/0x1810 kernel/signal.c:2936 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: 0033:0x7f7b60d7def9 RSP: 002b:00007f7b61b9e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f7b60f35f88 RCX: 00007f7b60d7def9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7b60f35f88 RBP: 00007f7b60f35f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7b60f35f8c R13: 0000000000000000 R14: 00007ffd396f2c10 R15: 00007ffd396f2cf8 rcu: rcu_preempt kthread starved for 10506 jiffies! g59753 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:24784 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.11.0-syzkaller-08829-gaf9c191ac2a0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:preempt_count_sub+0x0/0x170 kernel/sched/core.c:5805 Code: 8c 77 ff ff ff 48 c7 c7 70 88 1b 90 e8 89 45 98 00 e9 66 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 56 53 89 fb 48 c7 c0 40 c9 37 9a 48 c1 e8 03 49 be RSP: 0018:ffffc900001e6308 EFLAGS: 00000206 RAX: ffffc900001e8000 RBX: ffffc900001e63f0 RCX: ffffc900001e6d78 RDX: dffffc0000000000 RSI: ffffc900001e0000 RDI: 0000000000000001 RBP: ffffc900001e63e0 R08: ffffc900001e6d60 R09: 0000000000000000 R10: ffffc900001e6430 R11: fffff5200003cc88 R12: dffffc0000000000 R13: ffffc900001e63e0 R14: ffffc900001e0000 R15: ffffc900001e6d70 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000005a6cc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x18e6/0x22d0 arch/x86/kernel/unwind_orc.c:672 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_noprof+0x135/0x2a0 mm/slub.c:4142 __nf_conntrack_alloc+0x8f/0x380 net/netfilter/nf_conntrack_core.c:1631 init_conntrack+0x3c3/0x1310 net/netfilter/nf_conntrack_core.c:1722 resolve_normal_ct net/netfilter/nf_conntrack_core.c:1842 [inline] nf_conntrack_in+0xd5c/0x1890 net/netfilter/nf_conntrack_core.c:1994 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 __ip_local_out+0x3d9/0x4e0 net/ipv4/ip_output.c:119 ip_local_out+0x26/0x70 net/ipv4/ip_output.c:128 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: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 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 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