kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 7521 Comm: syz-executor4 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:ffff88013e09f8d8 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff88013e09f9f8 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: ffffffff81cdbc5b RDI: 0000000000000030 RBP: ffff88013e09f9c8 R08: ffff88013e090200 R09: fffffbfff12c24e5 R10: fffffbfff12c24e5 R11: ffffffff8961272b R12: ffff88013e78e340 R13: 1ffff10027c13f20 R14: 0000000000000000 R15: ffff88013e09fadc FS: 00007fb1bb41e700(0000) GS:ffff8801dad00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 00000001c03d8000 CR4: 00000000001406e0 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:00007fb1bb41dc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007fb1bb41e6d4 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: 'loop3' (0000000025919370): kobject_uevent_env kobject: 'loop3' (0000000025919370): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop0' (000000006467f0ef): kobject_uevent_env ---[ end trace e6bd115e18b86625 ]--- kobject: 'loop0' (000000006467f0ef): fill_kobj_path: path = '/devices/virtual/block/loop0' RIP: 0010:reconfigure_super+0x48e/0xbb0 fs/super.c:981 kobject: 'loop2' (000000003e9df5d5): kobject_uevent_env 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: 'loop2' (000000003e9df5d5): fill_kobj_path: path = '/devices/virtual/block/loop2' RSP: 0018:ffff88013e09f8d8 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff88013e09f9f8 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: ffffffff81cdbc5b RDI: 0000000000000030 RBP: ffff88013e09f9c8 R08: ffff88013e090200 R09: fffffbfff12c24e5 R10: fffffbfff12c24e5 R11: ffffffff8961272b R12: ffff88013e78e340 R13: 1ffff10027c13f20 R14: 0000000000000000 R15: ffff88013e09fadc kobject: 'loop1' (000000001d74049e): kobject_uevent_env kobject: 'loop1' (000000001d74049e): fill_kobj_path: path = '/devices/virtual/block/loop1' FS: 00007fb1bb41e700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 kobject: 'loop5' (0000000091c3893d): kobject_uevent_env kobject: 'loop5' (0000000091c3893d): fill_kobj_path: path = '/devices/virtual/block/loop5' CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f540b6d1ea0 CR3: 00000001c03d8000 CR4: 00000000001406f0