rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10544 ticks this GP) idle=b2a/1/0x4000000000000000 softirq=40071/40073 fqs=5238 
	(t=10502 jiffies g=59761 q=1696)
NMI backtrace for cpu 0
CPU: 0 PID: 21550 Comm: syz-executor.0 Not tainted 5.11.0-rc3-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:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x1f4/0x230 kernel/rcu/tree_stall.h:337
 print_cpu_stall kernel/rcu/tree_stall.h:569 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:643 [inline]
 rcu_pending kernel/rcu/tree.c:3751 [inline]
 rcu_sched_clock_irq.cold+0x48e/0xedf kernel/rcu/tree.c:2580
 update_process_times+0x16d/0x200 kernel/time/timer.c:1782
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369
 __run_hrtimer kernel/time/hrtimer.c:1519 [inline]
 __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1583
 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102
 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline]
 sysvec_apic_timer_interrupt+0x48/0x100 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
RIP: 0010:sctp_transport_lower_cwnd+0x23b/0x6e0 net/sctp/transport.c:500
Code: f0 03 00 00 41 c7 84 24 d4 00 00 00 00 00 00 00 0f 1f 44 00 00 e8 a5 38 50 f9 5b 5d 41 5c 41 5d 41 5e e9 98 38 50 f9 83 fb 03 <75> a1 e8 8e 38 50 f9 49 8d bc 24 cc 00 00 00 48 b8 00 00 00 00 00
RSP: 0018:ffffc900000079f0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000004
RDX: 0000000000000000 RSI: ffff888058bd0000 RDI: 0000000000000003
RBP: ffff88805d078000 R08: ffffffff8a5ffcc0 R09: ffffffff88228f3b
R10: 0000000000000004 R11: 0000000000000003 R12: ffff88801c9b9000
R13: 0000000000000022 R14: ffff88805d078000 R15: dffffc0000000000
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1642 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline]
 sctp_do_sm+0x33dc/0x5120 net/sctp/sm_sideeffect.c:1156
 sctp_generate_heartbeat_event+0x2b5/0x490 net/sctp/sm_sideeffect.c:391
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417
 expire_timers kernel/time/timer.c:1462 [inline]
 __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731
 __run_timers kernel/time/timer.c:1712 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744
 __do_softirq+0x2bc/0xa29 kernel/softirq.c:343
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:226 [inline]
 __irq_exit_rcu kernel/softirq.c:420 [inline]
 irq_exit_rcu+0x134/0x200 kernel/softirq.c:432
 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:199
Code: 0f 1f 44 00 00 55 48 8b 74 24 08 48 89 fd 48 83 c7 18 e8 6e 03 5d f8 48 89 ef e8 36 b8 5d f8 e8 81 da 7c f8 fb bf 01 00 00 00 <e8> e6 be 51 f8 65 8b 05 ef 2d 06 77 85 c0 74 02 5d c3 e8 5b 83 04
RSP: 0018:ffffc90003477828 EFLAGS: 00000202
RAX: 000000000002c3fb RBX: 0000000000000001 RCX: ffffffff81584977
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001
RBP: ffff8880b9e34c40 R08: 0000000000000001 R09: ffffffff8ed30857
R10: fffffbfff1da610a R11: 0000000000000000 R12: ffff8880b9e34c40
R13: ffff88802122b780 R14: 0000000000000000 R15: ffff888058bd0000
 finish_lock_switch kernel/sched/core.c:4065 [inline]
 finish_task_switch.isra.0+0x158/0x7e0 kernel/sched/core.c:4182
 context_switch kernel/sched/core.c:4316 [inline]
 __schedule+0x914/0x21a0 kernel/sched/core.c:5064
 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:5326
 irqentry_exit_cond_resched kernel/entry/common.c:393 [inline]
 irqentry_exit_cond_resched kernel/entry/common.c:385 [inline]
 irqentry_exit+0x7a/0xa0 kernel/entry/common.c:423
 asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:654
RIP: 0010:might_alloc include/linux/sched/mm.h:196 [inline]
RIP: 0010:slab_pre_alloc_hook mm/slab.h:493 [inline]
RIP: 0010:slab_alloc_node mm/slub.c:2816 [inline]
RIP: 0010:__kmalloc_node_track_caller+0x2fe/0x3f0 mm/slub.c:4495
Code: ff ff 4d 85 c0 0f 84 db fe ff ff 41 8b 7e 28 ba 08 00 00 00 31 f6 4c 01 c7 e8 9e 74 27 02 4c 8b 44 24 10 e9 be fe ff ff 31 d2 <be> c4 00 00 00 48 c7 c7 56 86 ca 8a e8 c1 6d 98 ff e9 54 fd ff ff
RSP: 0018:ffffc90003477a30 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000082cc0 RCX: ffffc900034779b8
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000082cc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000280
R13: 00000000ffffffff R14: ffff888010041140 R15: ffff888028689900
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xae/0x5a0 net/core/skbuff.c:210
 alloc_skb_fclone include/linux/skbuff.h:1149 [inline]
 sk_stream_alloc_skb+0x109/0xc30 net/ipv4/tcp.c:888
 tcp_sendmsg_locked+0xc00/0x2d90 net/ipv4/tcp.c:1310
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1459
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 __sys_sendto+0x21c/0x320 net/socket.c:1975
 __do_sys_sendto net/socket.c:1987 [inline]
 __se_sys_sendto net/socket.c:1983 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1983
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e219
Code: 0d b4 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0e812a4c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045e219
RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000005
RBP: 000000000119bfd8 R08: 0000000000000000 R09: 0000000009000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c
R13: 00007ffda2abfcff R14: 00007f0e812a59c0 R15: 000000000119bf8c