rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6720/1:b..l rcu: (detected by 0, t=10503 jiffies, g=18225, q=319 ncpus=2) task:syz-executor.3 state:R running task stack:24624 pid:6720 tgid:6705 ppid:5110 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7067 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_pc+0x38/0x60 kernel/kcov.c:210 Code: 05 e5 f3 75 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 35 8b 82 1c 16 00 00 85 c0 74 2b 8b 82 f8 15 00 00 83 f8 02 75 20 <48> 8b 8a 00 16 00 00 8b 92 fc 15 00 00 48 8b 01 48 83 c0 01 48 39 RSP: 0018:ffffc900033ef278 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff888022bdb640 RCX: ffffffff890bcb9f RDX: ffff888029d01e00 RSI: ffffffff890bcc1c RDI: 0000000000000001 RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000001 R12: ffff8880226d7800 R13: ffffc900033ef530 R14: 0000000000000028 R15: 1ffff9200067de52 udplite_error net/netfilter/nf_conntrack_proto_udp.c:171 [inline] nf_conntrack_udplite_packet+0x2ac/0x9f0 net/netfilter/nf_conntrack_proto_udp.c:191 nf_conntrack_handle_packet net/netfilter/nf_conntrack_core.c:1934 [inline] nf_conntrack_in+0x87c/0x1860 net/netfilter/nf_conntrack_core.c:2011 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] __ip6_local_out+0x42a/0x900 net/ipv6/output_core.c:143 ip6_local_out+0x2a/0x4a0 net/ipv6/output_core.c:153 ip6_send_skb+0xcd/0x2d0 net/ipv6/ip6_output.c:1955 udp_v6_send_skb+0x96e/0x1990 net/ipv6/udp.c:1294 udpv6_sendmsg+0x2544/0x3030 net/ipv6/udp.c:1590 inet6_sendmsg+0x105/0x140 net/ipv6/af_inet6.c:661 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x692/0xc90 net/socket.c:2585 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2639 __sys_sendmmsg+0x1a1/0x450 net/socket.c:2725 __do_sys_sendmmsg net/socket.c:2754 [inline] __se_sys_sendmmsg net/socket.c:2751 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2751 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f555c67cf69 RSP: 002b:00007f555d4330c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f555c7b4120 RCX: 00007f555c67cf69 RDX: 0000000000006c00 RSI: 0000000020007e40 RDI: 0000000000000008 RBP: 00007f555c6da6fe R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f555c7b4120 R15: 00007ffed0d31218 rcu: rcu_preempt kthread starved for 10527 jiffies! g18225 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:27680 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2000 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2202 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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 PID: 0 Comm: swapper/1 Not tainted 6.10.0-rc2-syzkaller-00366-g771ed66105de #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:__kasan_check_read+0x0/0x20 mm/kasan/shadow.c:30 Code: c3 cc cc cc cc 48 83 c4 60 48 c7 c7 f0 14 27 8d 5b 5d 41 5c e9 e1 93 84 ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 89 f6 31 d2 e9 2f f1 ff ff 66 66 2e 0f 1f RSP: 0018:ffffc90000a18de8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff8153c6e6 RDX: ffff888017e98000 RSI: 0000000000000008 RDI: ffffffff8fe46a10 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000007 R10: 0000000000000001 R11: 0000000000000003 R12: ffff8880210e8000 R13: 0000000000000000 R14: 0000000000000004 R15: 000000000003d94c FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32d2b000 CR3: 00000000223d4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:571 [inline] cpu_online include/linux/cpumask.h:1181 [inline] trace_signal_generate+0x6f/0x210 include/trace/events/signal.h:50 __send_signal_locked+0x579/0x11c0 kernel/signal.c:1187 do_send_sig_info kernel/signal.c:1301 [inline] group_send_sig_info+0x2aa/0x300 kernel/signal.c:1451 do_bpf_send_signal+0x9a/0x1d0 kernel/trace/bpf_trace.c:838 irq_work_single+0x1bc/0x260 kernel/irq_work.c:221 irq_work_run_list+0x92/0xc0 kernel/irq_work.c:252 irq_work_run+0x58/0xd0 kernel/irq_work.c:261 __sysvec_irq_work+0x8c/0x410 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x90/0xb0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 RIP: 0010:finish_task_switch.isra.0+0x220/0xcc0 kernel/sched/core.c:5282 Code: a9 0a 00 00 44 8b 0d 37 4d 86 0e 45 85 c9 0f 85 c0 01 00 00 48 89 df e8 ae f8 ff ff e8 d9 e6 36 00 fb 65 48 8b 1d 80 89 a5 7e <48> 8d bb f8 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc900001a7c08 EFLAGS: 00000202 RAX: 000000000029a751 RBX: ffff888017e98000 RCX: 1ffffffff1fc84f1 RDX: 0000000000000000 RSI: ffffffff8b2caf60 RDI: ffffffff8b9000c0 RBP: ffffc900001a7c50 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8fe46a17 R11: 0000000000000000 R12: ffff8880b933f978 R13: ffff8880210e8000 R14: 0000000000000000 R15: ffff8880b923ec00 context_switch kernel/sched/core.c:5411 [inline] __schedule+0xf1d/0x5d00 kernel/sched/core.c:6745 schedule_idle+0x59/0x90 kernel/sched/core.c:6863 do_idle+0x287/0x3f0 kernel/sched/idle.c:360 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x220/0x2b0 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x148 sched: RT throttling activated