BUG: unable to handle kernel paging request in init_srcu_struct_fields

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    65e08c5e8631 Merge tag 'linux-kselftest-4.20-rc7' of git:/..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16ca3d2b400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
dashboard link: https://syzkaller.appspot.com/bug?extid=010232b93d20ef8abde5
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+010232b93d20ef8abde5@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: unable to handle kernel paging request at ffffc90013465878
PGD 1da95a067 P4D 1da95a067 PUD 1da95b067 PMD 1bfe03067 PTE 0
kobject: 'kvm' (000000003b7ad1f2): kobject_uevent_env
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 31204 Comm: syz-executor4 Not tainted 4.20.0-rc6+ #372
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
kobject: 'kvm' (000000003b7ad1f2): kobject_uevent_env
RIP: 0010:init_srcu_struct_nodes kernel/rcu/srcutree.c:161 [inline]
RIP: 0010:init_srcu_struct_fields+0xd03/0x1470 kernel/rcu/srcutree.c:191
kobject: 'kvm' (000000003b7ad1f2): kobject_uevent_env
Code: 88 00 00 00 48 89 f8 48 c1 e8 03 0f b6 04 18 84 c0 74 08 3c 03 0f 8e  
0a 04 00 00 49 8d be 98 01 00 00 44 89 e1 b8 01 00 00 00 <41> 2b 8d 88 00  
00 00 48 89 fa 48 c1 ea 03 d3 e0 80 3c 1a 00 48 98
RSP: 0018:ffff888182a37420 EFLAGS: 00010246
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8881daf00198
RBP: ffff888182a37600 R08: ffff8881b89ec140 R09: 0000000000000000
R10: ffffed103b5c5b5f R11: ffff8881dae2dafb R12: 0000000000000001
kobject: 'kvm' (000000003b7ad1f2): fill_kobj_path: path  
= '/devices/virtual/misc/kvm'
R13: ffffc900134657f0 R14: ffff8881daf00000 R15: ffff8881daf000f0
FS:  00007f333e7d7700(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90013465878 CR3: 00000001c01eb000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kobject: 'kvm' (000000003b7ad1f2): fill_kobj_path: path  
= '/devices/virtual/misc/kvm'
kobject: 'kvm' (000000003b7ad1f2): kobject_uevent_env
kobject: 'kvm' (000000003b7ad1f2): fill_kobj_path: path  
= '/devices/virtual/misc/kvm'
kobject: 'kvm' (000000003b7ad1f2): fill_kobj_path: path  
= '/devices/virtual/misc/kvm'
 __init_srcu_struct+0x54/0x60 kernel/rcu/srcutree.c:207
kobject: 'kvm' (000000003b7ad1f2): kobject_uevent_env
 kvm_page_track_init+0x27/0x60 arch/x86/kvm/page_track.c:177
 kvm_arch_init_vm+0x5f0/0x790 arch/x86/kvm/x86.c:9024
kobject: 'kvm' (000000003b7ad1f2): fill_kobj_path: path  
= '/devices/virtual/misc/kvm'
kobject: 'kvm' (000000003b7ad1f2): kobject_uevent_env
 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:641 [inline]
 kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3197  
[inline]
 kvm_dev_ioctl+0x4c4/0x1ae0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3249
kobject: 'kvm' (000000003b7ad1f2): kobject_uevent_env
kobject: 'kvm' (000000003b7ad1f2): kobject_uevent_env
kobject: 'kvm' (000000003b7ad1f2): kobject_uevent_env
kobject: 'kvm' (000000003b7ad1f2): fill_kobj_path: path  
= '/devices/virtual/misc/kvm'
kobject: 'kvm' (000000003b7ad1f2): fill_kobj_path: path  
= '/devices/virtual/misc/kvm'
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696
kobject: 'kvm' (000000003b7ad1f2): fill_kobj_path: path  
= '/devices/virtual/misc/kvm'
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457679
Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f333e7d6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457679
RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000007
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f333e7d76d4
R13: 00000000004c00fe R14: 00000000004d1138 R15: 00000000ffffffff
Modules linked in:
CR2: ffffc90013465878
---[ end trace 6d1d73f0a8f2db3c ]---
RIP: 0010:init_srcu_struct_nodes kernel/rcu/srcutree.c:161 [inline]
RIP: 0010:init_srcu_struct_fields+0xd03/0x1470 kernel/rcu/srcutree.c:191
Code: 88 00 00 00 48 89 f8 48 c1 e8 03 0f b6 04 18 84 c0 74 08 3c 03 0f 8e  
0a 04 00 00 49 8d be 98 01 00 00 44 89 e1 b8 01 00 00 00 <41> 2b 8d 88 00  
00 00 48 89 fa 48 c1 ea 03 d3 e0 80 3c 1a 00 48 98
RSP: 0018:ffff888182a37420 EFLAGS: 00010246
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8881daf00198
RBP: ffff888182a37600 R08: ffff8881b89ec140 R09: 0000000000000000
R10: ffffed103b5c5b5f R11: ffff8881dae2dafb R12: 0000000000000001
R13: ffffc900134657f0 R14: ffff8881daf00000 R15: ffff8881daf000f0
FS:  00007f333e7d7700(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90013465878 CR3: 00000001c01eb000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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