rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=136/1/0x4000000000000002 softirq=10847/10847 fqs=1 
	(t=10501 jiffies g=6513 q=131)
rcu: rcu_preempt kthread starved for 10500 jiffies! g6513 f0x0 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
NMI backtrace for cpu 0
CPU: 0 PID: 8193 Comm: syz-executor.0 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0xe25/0x1ad0 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
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x27/0x50 kernel/kcov.c:105
Code: 5d c3 cc 48 8b 04 24 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 b8 81 8b 7e f7 c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 83 fa 02 75 21 <48> 8b 91 88 13 00 00 48 8b 32 48 8d 7e 01 8b 89 84 13 00 00 48 39
RSP: 0018:ffffc900026ff720 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81487326 RBX: ffffea00027fb580 RCX: ffff8880a0164040
RDX: 0000000000000002 RSI: 00000000fffffffc RDI: ffffea00027fb580
RBP: ffffc900026ff748 R08: 000000000003a768 R09: ffffed1012728ef7
R10: ffffed1012728ef7 R11: 0000000000000000 R12: ffff8880a977b420
R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880939477a8
 free_thread_stack+0x168/0x590 kernel/fork.c:280
 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:debug_lockdep_rcu_enabled+0x0/0xe0 kernel/rcu/update.c:250
Code: 07 80 c1 03 38 c1 7c e3 48 c7 c7 f4 18 81 89 e8 66 f0 4e 00 eb d5 0f 1f 40 00 55 48 89 e5 e8 a7 b7 00 00 e8 a2 b8 00 00 5d c3 <55> 48 89 e5 41 57 41 56 53 48 c7 c0 5c c0 43 89 48 c1 e8 03 49 bf
RSP: 0018:ffffc900026ff9a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff8766a21d RBX: 0000000000000030 RCX: 0000000000040000
RDX: ffffc90001fd9000 RSI: 0000000000004bc6 RDI: 0000000000004bc7
RBP: ffffc900026ffa80 R08: ffffffff8766a1db R09: fffffbfff128b316
R10: fffffbfff128b316 R11: 0000000000000000 R12: 1ffff1101347c300
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000001
 sctp_assoc_add_peer+0xb94/0x1600 net/sctp/associola.c:709
 sctp_connect_new_asoc+0x2a0/0x610 net/sctp/socket.c:1078
 __sctp_connect+0x560/0x1180 net/sctp/socket.c:1176
 __sctp_setsockopt_connectx net/sctp/socket.c:1322 [inline]
 sctp_getsockopt_connectx3 net/sctp/socket.c:1407 [inline]
 sctp_getsockopt+0x961a/0x11770 net/sctp/socket.c:8079
 sock_common_getsockopt+0x99/0xb0 net/core/sock.c:3108
 __sys_getsockopt+0x24c/0x2b0 net/socket.c:2162
 __do_sys_getsockopt net/socket.c:2177 [inline]
 __se_sys_getsockopt net/socket.c:2174 [inline]
 __x64_sys_getsockopt+0xbf/0xd0 net/socket.c:2174
 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:00007fb0ff4b4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a679
RDX: 000000000000006f RSI: 0000000000000084 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000020000180 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00007fb0ff4b56d4
R13: 00000000004ceac0 R14: 00000000004d6410 R15: 00000000ffffffff