rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=48f/1/0x4000000000000000 softirq=21399/21400 fqs=0 (t=17423 jiffies g=24069 q=983) rcu: rcu_preempt kthread starved for 17423 jiffies! g24069 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:I stack:26288 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xbfd/0x11d0 kernel/sched/core.c:6287 schedule+0x14b/0x210 kernel/sched/core.c:6366 schedule_timeout+0x1aa/0x2f0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x1fd/0x770 kernel/rcu/tree.c:1957 rcu_gp_kthread+0xa5/0x340 kernel/rcu/tree.c:2130 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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: 175 Comm: kworker/u4:4 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x33/0x60 kernel/kcov.c:197 Code: c0 ef 01 00 65 8b 15 a4 0a 81 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 3c 15 00 00 00 74 2c 8b 91 18 15 00 00 <83> fa 02 75 21 48 8b 91 20 15 00 00 48 8b 32 48 8d 7e 01 8b 89 1c RSP: 0018:ffffc900011ff818 EFLAGS: 00000246 RAX: ffffffff8175478a RBX: 1ffff11017387085 RCX: ffff8880147dd580 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900011ff960 R08: ffffffff8175474e R09: ffffffff842c5b80 R10: 0000000000000009 R11: ffff8880147dd580 R12: 0000000000000000 R13: ffff8880b9c38428 R14: 1ffff110173a64a8 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559d7f8b1960 CR3: 000000000c68e000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:440 [inline] smp_call_function_many_cond+0xaaa/0xd60 kernel/smp.c:969 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:929 [inline] text_poke_bp_batch+0x310/0x940 arch/x86/kernel/alternative.c:1114 text_poke_flush arch/x86/kernel/alternative.c:1268 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1275 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12d/0x250 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate+0xbf/0x440 mm/kfence/core.c:623 process_one_work+0x853/0x1140 kernel/workqueue.c:2297 worker_thread+0xac1/0x1320 kernel/workqueue.c:2444 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 0 CPU: 0 PID: 17699 Comm: syz-executor.3 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105 nmi_cpu_backtrace+0x405/0x430 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x22d/0x390 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq+0x1dc2/0x2b40 kernel/rcu/tree.c:2599 update_process_times+0x197/0x200 kernel/time/timer.c:1785 tick_sched_handle kernel/time/tick-sched.c:226 [inline] tick_sched_timer+0x27d/0x420 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:module_put+0x0/0xa0 kernel/module.c:1089 Code: 40 96 93 8c e9 e1 8f e0 ff 90 53 48 89 f3 e8 17 00 00 00 e8 c2 7c 55 00 48 89 df e8 0a 88 d7 ff 66 2e 0f 1f 84 00 00 00 00 00 <41> 56 53 48 85 ff 74 69 49 89 fe bf 01 00 00 00 e8 3b 3e e2 ff 49 RSP: 0018:ffffc9000945f9f8 EFLAGS: 00000246 RAX: 000000008b845901 RBX: ffffffff8b846050 RCX: 0000000000040000 RDX: ffff888020338000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8b845908 R08: ffffffff87ee582c R09: ffff888020132938 R10: ffffed1004026529 R11: 0000000000000000 R12: ffff8880980cec00 R13: dffffc0000000000 R14: 0000000000000002 R15: 1ffffffff1708c0a __sock_create+0x5fa/0x8d0 net/socket.c:1479 inet_ctl_sock_create+0x96/0x1e0 net/ipv4/af_inet.c:1654 igmp_net_init+0xb7/0x150 net/ipv4/igmp.c:3022 ops_init+0x313/0x430 net/core/net_namespace.c:140 setup_net+0x35b/0x9d0 net/core/net_namespace.c:326 copy_net_ns+0x359/0x5c0 net/core/net_namespace.c:470 create_new_namespaces+0x4ce/0xa00 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x180 kernel/nsproxy.c:226 ksys_unshare+0x57d/0xb50 kernel/fork.c:3005 __do_sys_unshare kernel/fork.c:3079 [inline] __se_sys_unshare kernel/fork.c:3077 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3077 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f648dfb0188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c060000 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffd443577cf R14: 00007f648dfb0300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: c0 ef 01 shr $0x1,%bh 3: 00 65 8b add %ah,-0x75(%rbp) 6: 15 a4 0a 81 7e adc $0x7e810aa4,%eax b: f7 c2 00 01 ff 00 test $0xff0100,%edx 11: 74 11 je 0x24 13: f7 c2 00 01 00 00 test $0x100,%edx 19: 74 35 je 0x50 1b: 83 b9 3c 15 00 00 00 cmpl $0x0,0x153c(%rcx) 22: 74 2c je 0x50 24: 8b 91 18 15 00 00 mov 0x1518(%rcx),%edx * 2a: 83 fa 02 cmp $0x2,%edx <-- trapping instruction 2d: 75 21 jne 0x50 2f: 48 8b 91 20 15 00 00 mov 0x1520(%rcx),%rdx 36: 48 8b 32 mov (%rdx),%rsi 39: 48 8d 7e 01 lea 0x1(%rsi),%rdi 3d: 8b .byte 0x8b 3e: 89 .byte 0x89 3f: 1c .byte 0x1c