rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=6481, q=296) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294953838-4294943336), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.0 R running task 27768 8174 8150 0x0000400a Call Trace: sched_show_task+0x40f/0x560 kernel/sched/core.c:5954 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline] check_cpu_stall kernel/rcu/tree_stall.h:538 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0x1861/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:free_thread_stack+0x16d/0x590 kernel/fork.c:284 Code: c3 08 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 25 a4 69 00 48 8b 3b be fc ff ff ff e8 28 04 00 00 43 80 3c 2e 00 <74> 08 4c 89 e7 e8 09 a4 69 00 49 8b 1c 24 48 83 c3 08 48 89 d8 48 RSP: 0018:ffffc900023a73c8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81487433 RBX: ffff88809fac4288 RCX: 0000000000040000 RDX: ffffc9000202a000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc900023a7400 R08: 000000000003a768 R09: ffffed1012805eb7 R10: ffffed1012805eb7 R11: 0000000000000000 R12: ffff88809fac4320 R13: dffffc0000000000 R14: 1ffff11013f58864 R15: ffff88809402f5a8 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338 retint_kernel+0x1b/0x2b RIP: 0010:stack_trace_consume_entry+0x11f/0x260 kernel/stacktrace.c:93 Code: ff df 80 3c 08 00 74 08 4c 89 e7 e8 db 75 4c 00 4d 8b 3c 24 4c 89 f2 41 8d 5e 01 49 bc 00 00 00 00 00 fc ff df 43 8a 44 25 00 <84> c0 0f 85 ea 00 00 00 4c 8b 6d c8 41 89 5d 00 49 8d 1c d7 48 89 RSP: 0018:ffffc900023a7610 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02 RAX: 1ffff92000474e00 RBX: 0000000000000005 RCX: dffffc0000000000 RDX: 0000000000000004 RSI: 0000000000001276 RDI: 0000000000001277 RBP: ffffc900023a7660 R08: ffffffff81659cc5 R09: ffffc900023a7670 R10: fffff52000474eda R11: 0000000000000000 R12: dffffc0000000000 R13: 1ffff92000474ee4 R14: 0000000000000004 R15: ffffc900023a7780 arch_stack_walk+0xa8/0xe0 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xb6/0x150 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:71 [inline] set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:512 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:520 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x1f5/0x2e0 mm/slab.c:3484 kmem_cache_zalloc include/linux/slab.h:660 [inline] dccp_ackvec_alloc+0x26/0x120 net/dccp/ackvec.c:19 dccp_hdlr_ackvec+0xbc/0x100 net/dccp/feat.c:85 __dccp_feat_activate net/dccp/feat.c:339 [inline] dccp_feat_activate_values+0x5af/0xce0 net/dccp/feat.c:1538 dccp_rcv_request_sent_state_process net/dccp/input.c:468 [inline] dccp_rcv_state_process+0x1185/0x1a60 net/dccp/input.c:676 dccp_v4_do_rcv+0xf5/0x190 net/dccp/ipv4.c:684 sk_backlog_rcv include/net/sock.h:949 [inline] __release_sock+0x1c1/0x4a0 net/core/sock.c:2437 release_sock+0x65/0x1c0 net/core/sock.c:2953 inet_wait_for_connect net/ipv4/af_inet.c:588 [inline] __inet_stream_connect+0x538/0xc40 net/ipv4/af_inet.c:680 inet_stream_connect+0x63/0xa0 net/ipv4/af_inet.c:719 __sys_connect_file+0x279/0x2f0 net/socket.c:1848 __sys_connect net/socket.c:1861 [inline] __do_sys_connect net/socket.c:1872 [inline] __se_sys_connect net/socket.c:1869 [inline] __x64_sys_connect+0xa2/0xf0 net/socket.c:1869 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a679 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fab447f9c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000010 RSI: 0000000020e5c000 RDI: 0000000000000004 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fab447fa6d4 R13: 00000000004c0e08 R14: 00000000004d4a60 R15: 00000000ffffffff rcu: rcu_preempt kthread starved for 10502 jiffies! g6481 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29032 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352