------------[ cut here ]------------
WARNING: CPU: 1 PID: 11894 at kernel/rcu/tree_stall.h:1050 rcu_check_gp_start_stall+0x2e4/0x470
Modules linked in:
CPU: 1 UID: 0 PID: 11894 Comm: syz.2.1532 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470
Code: ff ff 48 c7 c7 20 94 b0 99 be 04 00 00 00 e8 e3 de 7c 00 4c 89 f7 b8 01 00 00 00 87 05 15 87 09 18 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff 80 f4 13 8e 74 47 48 c7 c0 60 f3 a3 8f 48 c1 e8
RSP: 0018:ffffc900001e0bb8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000a02 RCX: ffffffff81a70cfd
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8e13f480
RBP: ffffc900001e0e30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff3361284 R12: 0000000000002904
R13: 1ffff11026cc75f2 R14: ffffffff8e13f480 R15: dffffc0000000000
FS:  00007f4ba6bed6c0(0000) GS:ffff8881a3c0f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49fa9d7dac CR3: 000000003fb3c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_core+0x5fa/0x1770
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:native_queued_spin_lock_slowpath+0xaf/0x8e0
Code: 00 00 00 c7 44 24 60 00 00 00 00 0f 1f 44 00 00 4c 8d 74 24 60 49 89 df 49 c1 ef 03 41 bd 01 00 00 00 eb 06 89 44 24 60 f3 90 <48> 89 df be 04 00 00 00 e8 54 1d a6 f6 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc9000460ee80 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff8881000e0068 RCX: ffffffff8b7dce5c
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8881000e0068
RBP: ffffc9000460ef78 R08: ffff8881000e006b R09: 1ffff1102001c00d
R10: dffffc0000000000 R11: ffffed102001c00e R12: 1ffff920008c1dd8
R13: 0000000000000001 R14: ffffc9000460eee0 R15: 1ffff1102001c00d
 queued_spin_lock_slowpath+0x43/0x50
 do_raw_spin_lock+0x21f/0x290
 __kernfs_new_node+0x10a/0x7e0
 kernfs_new_node+0x102/0x210
 __kernfs_create_file+0x4b/0x2e0
 sysfs_add_file_mode_ns+0x238/0x300
 internal_create_group+0x66d/0x1110
 sysfs_create_groups+0x59/0x120
 ib_setup_port_attrs+0xd96/0x2070
 add_one_compat_dev+0x3d6/0x5c0
 rdma_dev_init_net+0x1dd/0x270
 ops_init+0x35c/0x5c0
 setup_net+0x10c/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 copy_namespaces+0x438/0x4b0
 copy_process+0x1733/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4ba5d8ec29
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4ba6becfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f4ba5fd5fa0 RCX: 00007f4ba5d8ec29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f4ba5e11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f4ba5fd6038 R14: 00007f4ba5fd5fa0 R15: 00007ffea4824bb8
 </TASK>
