rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5214/1:b..l P7164/1:b..l rcu: (detected by 1, t=10503 jiffies, g=18201, q=1706951 ncpus=2) task:syz.3.272 state:R running task stack:23864 pid:7164 tgid:7161 ppid:5851 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6693 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6872 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6896 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:4459 dev_queue_xmit include/linux/netdevice.h:3094 [inline] __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 [inline] __netlink_deliver_tap+0x54d/0x7c0 net/netlink/af_netlink.c:325 netlink_deliver_tap+0x19d/0x1b0 net/netlink/af_netlink.c:338 __netlink_sendskb net/netlink/af_netlink.c:1265 [inline] netlink_sendskb+0x68/0x140 net/netlink/af_netlink.c:1274 netlink_unicast+0x39d/0x990 net/netlink/af_netlink.c:1362 netlink_rcv_skb+0x262/0x430 net/netlink/af_netlink.c:2547 nfnetlink_rcv+0x297/0x2ab0 net/netfilter/nfnetlink.c:667 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2581 ___sys_sendmsg net/socket.c:2635 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2667 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: 0033:0x7f8addd7e759 RSP: 002b:00007f8adeb0d038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f8addf36058 RCX: 00007f8addd7e759 RDX: 0000000000040010 RSI: 0000000020000000 RDI: 0000000000000006 RBP: 00007f8adddf175e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8addf36058 R15: 00007f8ade05fa28 task:udevd state:R running task stack:23856 pid:5214 tgid:5214 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6693 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7015 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:preempt_count_sub+0x66/0x170 kernel/sched/core.c:5835 Code: c1 81 e1 ff ff ff 7f 39 d9 7c 27 81 fb fe 00 00 00 77 07 0f b6 c0 85 c0 74 5f 65 8b 05 6b 97 a0 7e f7 db 65 01 1d 62 97 a0 7e <5b> 41 5e c3 cc cc cc cc 90 e8 6c 4e 57 03 85 c0 74 3a 48 c7 c0 d0 RSP: 0018:ffffc900033ff258 EFLAGS: 00000297 RAX: 0000000080000001 RBX: 00000000ffffffff RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffc900033f8000 RDI: 0000000000000001 RBP: ffffc900033ff340 R08: ffffc900033fff00 R09: 0000000000000000 R10: ffffc900033ff390 R11: fffff5200067fe74 R12: dffffc0000000000 R13: ffffc900033ff340 R14: dffffc0000000000 R15: ffffc900033fff10 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 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:1127 [inline] free_unref_page+0xdf9/0x1140 mm/page_alloc.c:2657 __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] kzalloc_noprof include/linux/slab.h:1014 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822 security_inode_getattr+0x130/0x330 security/security.c:2373 vfs_getattr+0x2a/0x3b0 fs/stat.c:243 vfs_statx_path fs/stat.c:283 [inline] vfs_statx+0x18c/0x490 fs/stat.c:347 vfs_fstatat+0xe5/0x130 fs/stat.c:366 __do_sys_newfstatat fs/stat.c:530 [inline] __se_sys_newfstatat fs/stat.c:524 [inline] __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:524 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: 0033:0x7fdfe8b165f4 RSP: 002b:00007ffc41f7b838 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000557deac746d8 RCX: 00007fdfe8b165f4 RDX: 00007ffc41f7b848 RSI: 0000557deac64897 RDI: 00000000ffffff9c RBP: 0000557df71db448 R08: 0006273fcfb5c747 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 0006273fcfb5c747 R15: 0000557deac68dca rcu: rcu_preempt kthread starved for 6796 jiffies! g18201 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:24816 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6693 __schedule_loop kernel/sched/core.c:6770 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6785 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: 24 Comm: ksoftirqd/1 Not tainted 6.12.0-syzkaller-00239-gc6d64479d609 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:unwind_next_frame+0xd/0x22d0 arch/x86/kernel/unwind_orc.c:469 Code: 7c 91 4c 89 f7 e8 73 71 bd 00 eb 87 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 <53> 48 81 ec 98 00 00 00 49 89 fd 49 bc 00 00 00 00 00 fc ff df 48 RSP: 0018:ffffc900001e6510 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc900001e6540 RCX: ffffffff917c6000 RDX: dffffc0000000000 RSI: ffffffff8a215cdc RDI: ffffc900001e6540 RBP: ffffc900001e65d0 R08: 0000000000000004 R09: ffffc900001e6630 R10: ffffc900001e6590 R11: ffffffff8180a170 R12: ffff88801dab0000 R13: ffffffff8180a170 R14: ffffc900001e6620 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557df71e9d88 CR3: 000000007fb4c000 CR4: 00000000003526f0 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:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 dst_alloc+0x12b/0x190 net/core/dst.c:89 rt_dst_alloc net/ipv4/route.c:1612 [inline] __mkroute_output net/ipv4/route.c:2573 [inline] ip_route_output_key_hash_rcu+0x13cc/0x2390 net/ipv4/route.c:2795 ip_route_output_key_hash+0x193/0x2b0 net/ipv4/route.c:2624 __ip_route_output_key include/net/route.h:141 [inline] ip_route_output_flow+0x29/0x140 net/ipv4/route.c:2852 ip_route_output_key include/net/route.h:151 [inline] ip_route_me_harder+0x80d/0x1300 net/ipv4/netfilter.c:53 synproxy_send_tcp+0x356/0x6c0 net/netfilter/nf_synproxy_core.c:431 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:5670 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5783 process_backlog+0x662/0x15b0 net/core/dev.c:6115 __napi_poll+0xcb/0x490 net/core/dev.c:6779 napi_poll net/core/dev.c:6848 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6970 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