BUG: memory leak
unreferenced object 0xffff888018c85ac0 (size 16):
  comm "syz-executor.7", pid 9839, jiffies 4295828301 (age 15.783s)
  hex dump (first 16 bytes):
    b8 52 54 47 80 88 ff ff 00 60 88 23 80 88 ff ff  .RTG.....`.#....
  backtrace:
    [<00000000f22e8903>] kmalloc include/linux/slab.h:552 [inline]
    [<00000000f22e8903>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<0000000015e48ede>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<000000008f3c826b>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<000000000b1c8c85>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<00000000b88a0494>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<000000000f9c2059>] do_new_mount fs/namespace.c:2881 [inline]
    [<000000000f9c2059>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<000000009546d279>] do_mount fs/namespace.c:3224 [inline]
    [<000000009546d279>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<000000009546d279>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<000000009546d279>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<00000000962a993b>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<00000000ba31c430>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed