FYI, we noticed the following commit:

commit: 89e689f267b2c144d7b071443e01fa718727b962 ("kernfs, sysfs, cgroup, intel_rdt: Support fs_context")
https://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git mount-context

in testcase: trinity
with following parameters:

	runtime: 300s

test-description: Trinity is a linux system call fuzz tester.
test-url: http://codemonkey.org.uk/projects/trinity/


on test machine: qemu-system-i386 -enable-kvm -m 256M

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):


+------------------------------------------+------------+------------+
|                                          | a62d750e12 | 89e689f267 |
+------------------------------------------+------------+------------+
| boot_successes                           | 22         | 2          |
| boot_failures                            | 0          | 22         |
| kernel_BUG_at_fs/super.c                 | 0          | 22         |
| invalid_opcode:#[##]                     | 0          | 22         |
| EIP:vfs_get_tree                         | 0          | 22         |
| Kernel_panic-not_syncing:Fatal_exception | 0          | 22         |
+------------------------------------------+------------+------------+



[    2.580515] kernel BUG at fs/super.c:1703!
[    2.581033] invalid opcode: 0000 [#1]
[    2.581372] CPU: 0 PID: 1 Comm: init Not tainted 4.13.0-rc1-00020-g89e689f #1
[    2.581981] task: 8741e000 task.stack: 87420000
[    2.582400] EIP: vfs_get_tree+0x4d/0xe1
[    2.582736] EFLAGS: 00010246 CPU: 0
[    2.583052] EAX: 00000000 EBX: 83d3a8c8 ECX: 83d3ccc4 EDX: 7970b580
[    2.583599] ESI: 00000027 EDI: 00000000 EBP: 87421f28 ESP: 87421f20
[    2.584150]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
[    2.584619] CR0: 80050033 CR2: 6feff588 CR3: 0bcd4000 CR4: 00000690
[    2.585174] Call Trace:
[    2.585400]  do_mount+0x89e/0x8dc
[    2.585694]  ? strndup_user+0x27/0x3f
[    2.586016]  SyS_mount+0x52/0x76
[    2.586317]  do_int80_syscall_32+0x4c/0xd9
[    2.586680]  entry_INT80_32+0x2c/0x2c
[    2.586998] EIP: 0x6fef6c3e
[    2.587266] EFLAGS: 00000216 CPU: 0
[    2.587581] EAX: ffffffda EBX: 0804a3a9 ECX: 0804a3a1 EDX: 0804a3a9
[    2.588136] ESI: 0000000e EDI: 00000000 EBP: 77a30778 ESP: 77a306dc
[    2.588689]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
[    2.589176] Code: ff ff ff e9 aa 00 00 00 89 d8 ff d2 85 c0 79 e8 e9 9d 00 00 00 8b 13 89 d8 ff 52 18 85 c0 0f 88 8e 00 00 00 8b 43 08 85 c0 75 02 <0f> 0b 8b b0 94 00 00 00 83 be ac 00 00 00 00 75 02 0f ff 8b 43
[    2.590882] EIP: vfs_get_tree+0x4d/0xe1 SS:ESP: 0068:87421f20
[    2.591412] ---[ end trace 5e29087d876104ae ]---


To reproduce:

        git clone https://github.com/intel/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script  # job-script is attached in this email



Thanks,
Xiaolong