kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 21611 Comm: syz-executor0 Not tainted 4.19.0-rc3-next-20180913+ #73
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:reconfigure_super+0x48e/0xbb0 fs/super.c:981
Code: 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 62 05 00 00 48 ba 00 00 00 00 00 fc ff df 48 8b 03 48 8d 78 30 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 4d 05 00 00 48 8b 40 30 48 85 c0 48 89 85 20 ff
RSP: 0018:ffff8801436b78d8 EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffff8801436b79f8 RCX: 0000000000000006
RDX: dffffc0000000000 RSI: ffffffff81cdbc5b RDI: 0000000000000030
RBP: ffff8801436b79c8 R08: ffff8801364681c0 R09: fffffbfff12c24e5
R10: fffffbfff12c24e5 R11: ffffffff8961272b R12: ffff8801c200aec0
R13: 1ffff100286d6f20 R14: 0000000000000000 R15: ffff8801436b7adc
FS:  00007f3432f4c700(0000) GS:ffff8801dad00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bf22000 CR3: 00000001b9166000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 do_umount_root+0x2b1/0x320 fs/namespace.c:1434
 do_umount fs/namespace.c:1504 [inline]
 ksys_umount+0x8b6/0x1230 fs/namespace.c:1620
 __do_sys_umount fs/namespace.c:1631 [inline]
 __se_sys_umount fs/namespace.c:1629 [inline]
 __x64_sys_umount+0x54/0x80 fs/namespace.c:1629
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4572d9
Code: fd 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f3432f4bc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007f3432f4c6d4 RCX: 00000000004572d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 0000000000930280 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7ba8 R14: 00000000004caa53 R15: 0000000000000003
Modules linked in:
kobject: 'loop4' (000000007738e4ba): kobject_uevent_env
kobject: 'loop4' (000000007738e4ba): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop3' (0000000077a89153): kobject_uevent_env
kobject: 'rx-0' (000000006d5634ad): kobject_cleanup, parent 000000005d13f363
kobject: 'loop3' (0000000077a89153): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'rx-0' (000000006d5634ad): auto cleanup 'remove' event
kobject: 'rx-0' (000000006d5634ad): kobject_uevent_env
kobject: 'rx-0' (000000006d5634ad): fill_kobj_path: path = '/devices/virtual/net/syz_tun/queues/rx-0'
kobject: 'rx-0' (000000006d5634ad): auto cleanup kobject_del
---[ end trace 6e302a7f20848fe5 ]---
RIP: 0010:reconfigure_super+0x48e/0xbb0 fs/super.c:981
kobject: 'rx-0' (000000006d5634ad): calling ktype release
kobject: 'loop2' (0000000077d63ce6): kobject_uevent_env
kobject: 'rx-0': free name
Code: 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 62 05 00 00 48 ba 00 00 00 00 00 fc ff df 48 8b 03 48 8d 78 30 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 4d 05 00 00 48 8b 40 30 48 85 c0 48 89 85 20 ff
kobject: 'tx-0' (000000003951cb11): kobject_cleanup, parent 000000005d13f363
kobject: 'loop2' (0000000077d63ce6): fill_kobj_path: path = '/devices/virtual/block/loop2'
kobject: 'tx-0' (000000003951cb11): auto cleanup 'remove' event
kobject: 'tx-0' (000000003951cb11): kobject_uevent_env
kobject: 'tx-0' (000000003951cb11): fill_kobj_path: path = '/devices/virtual/net/syz_tun/queues/tx-0'
kobject: 'tx-0' (000000003951cb11): auto cleanup kobject_del
kobject: 'tx-0' (000000003951cb11): calling ktype release
RSP: 0018:ffff8801436b78d8 EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffff8801436b79f8 RCX: 0000000000000006
kobject: 'tx-0': free name
kobject: 'queues' (000000005d13f363): kobject_cleanup, parent           (null)
RDX: dffffc0000000000 RSI: ffffffff81cdbc5b RDI: 0000000000000030
kobject: 'queues' (000000005d13f363): calling ktype release
kobject: 'queues' (000000005d13f363): kset_release
kobject: 'queues': free name
kobject: 'syz_tun' (000000004d529424): kobject_uevent_env
RBP: ffff8801436b79c8 R08: ffff8801364681c0 R09: fffffbfff12c24e5
kobject: 'syz_tun' (000000004d529424): fill_kobj_path: path = '/devices/virtual/net/syz_tun'
R10: fffffbfff12c24e5 R11: ffffffff8961272b R12: ffff8801c200aec0
kobject: 'loop1' (000000009ecf959b): kobject_uevent_env
R13: 1ffff100286d6f20 R14: 0000000000000000 R15: ffff8801436b7adc
kobject: 'loop1' (000000009ecf959b): fill_kobj_path: path = '/devices/virtual/block/loop1'
FS:  00007f3432f4c700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000
kobject: 'syz_tun' (000000004d529424): kobject_cleanup, parent           (null)
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002175e80 CR3: 00000001b9166000 CR4: 00000000001406f0
kobject: 'syz_tun' (000000004d529424): calling ktype release
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400