rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=1aa4/1/0x4000000000000000 softirq=33877/33878 fqs=0 (detected by 0, t=10502 jiffies, g=41965, q=291 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3651 Comm: syz-executor.0 Not tainted 6.0.0-rc6-next-20220923-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 RIP: 0010:__remove_hrtimer+0x123/0x2a0 kernel/time/hrtimer.c:1117 Code: dc 07 e8 20 5a 10 00 44 89 e1 b8 fe ff ff ff 48 ba 00 00 00 00 00 fc ff df 49 8d 7e 44 d3 c0 48 89 f9 48 c1 e9 03 0f b6 0c 11 <48> 89 fa 83 e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 85 27 01 00 00 41 RSP: 0018:ffffc900001f0de8 EFLAGS: 00000803 RAX: 00000000fffffffd RBX: ffff88801f5e4340 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff816c39e0 RDI: ffff8880b9b2a584 RBP: ffff8880b9b2a640 R08: 0000000000000005 R09: 000000000000001f R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880b9b2a540 R15: 0000000000000000 FS: 000055555661e400(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbc6f17d1b8 CR3: 000000003cdb6000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1665 [inline] __hrtimer_run_queues+0x548/0xfb0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] __sysvec_apic_timer_interrupt+0x17c/0x640 arch/x86/kernel/apic/apic.c:1113 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:stack_trace_consume_entry+0xb/0x160 kernel/stacktrace.c:83 Code: 00 e9 51 fc ff ff 48 89 ee 48 c7 c7 a0 75 fa 8b e8 ca 2a d2 07 e9 1a fc ff ff e8 30 84 21 08 48 b8 00 00 00 00 00 fc ff df 55 <53> 48 89 fb 48 83 c7 10 48 89 fa 48 83 ec 08 48 c1 ea 03 0f b6 04 RSP: 0018:ffffc9000410f6a8 EFLAGS: 00000282 RAX: dffffc0000000000 RBX: ffffffff816b0660 RCX: 0000000000000000 RDX: 1ffff92000821ee0 RSI: ffffffff81bd182c RDI: ffffc9000410f770 RBP: ffffc9000410f740 R08: ffffffff8e6aa63c R09: ffffc9000410f6ec R10: fffff52000821ee2 R11: ffffc9000410fb68 R12: ffffc9000410f770 R13: 0000000000000000 R14: ffff888026d28000 R15: ffffea00021289c0 arch_stack_walk+0x6d/0xe0 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2a/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1669 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1695 slab_free mm/slub.c:3599 [inline] __kmem_cache_free+0xab/0x3b0 mm/slub.c:3612 __vunmap+0xae4/0xd30 mm/vmalloc.c:2721 __vfree+0x3c/0xd0 mm/vmalloc.c:2761 vfree+0x5a/0x90 mm/vmalloc.c:2792 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:868 [inline] get_entries net/ipv4/netfilter/ip_tables.c:1024 [inline] do_ipt_get_ctl+0x7fe/0x9d0 net/ipv4/netfilter/ip_tables.c:1663 nf_getsockopt+0x72/0xd0 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x185/0x1e0 net/ipv4/ip_sockglue.c:1796 tcp_getsockopt+0x95/0xf0 net/ipv4/tcp.c:4398 __sys_getsockopt+0x216/0x690 net/socket.c:2296 __do_sys_getsockopt net/socket.c:2311 [inline] __se_sys_getsockopt net/socket.c:2308 [inline] __x64_sys_getsockopt+0xba/0x150 net/socket.c:2308 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fbc6f08bc8a Code: 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe15efd1b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbc6f08bc8a RDX: 0000000000000041 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffe15efd1e0 R08: 00007ffe15efd1dc R09: ffffffffffff0000 R10: 00007ffe15efd240 R11: 0000000000000202 R12: 00007ffe15efd240 R13: 0000000000000003 R14: 00007ffe15efd1dc R15: 00007fbc6f182160 rcu: rcu_preempt kthread starved for 10502 jiffies! g41965 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:28184 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5194 [inline] __schedule+0xbd2/0x55b0 kernel/sched/core.c:6506 schedule+0xda/0x1b0 kernel/sched/core.c:6582 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1658 rcu_gp_kthread+0x236/0x360 kernel/rcu/tree.c:1857 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 6437 Comm: kworker/u4:52 Not tainted 6.0.0-rc6-next-20220923-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline] RIP: 0010:smp_call_function_many_cond+0x4b5/0x1140 kernel/smp.c:987 Code: 52 48 b9 00 00 00 00 00 fc ff df 48 8b 04 24 49 89 c5 83 e0 07 49 c1 ed 03 49 89 c4 49 01 cd 41 83 c4 03 e8 4d e7 0a 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 73 0a 00 00 8b 43 08 31 RSP: 0018:ffffc9000ae3f948 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9b402c0 RCX: 0000000000000000 RDX: ffff8880767ad7c0 RSI: ffffffff8171acb3 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000003 R13: ffffed1017368059 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6e1937d1b8 CR3: 000000000bc8e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1155 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1311 [inline] text_poke_bp_batch+0x233/0x6c0 arch/x86/kernel/alternative.c:1499 text_poke_flush arch/x86/kernel/alternative.c:1669 [inline] text_poke_flush arch/x86/kernel/alternative.c:1666 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1676 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:801 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:800 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:792 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306