BUG: memory leak
unreferenced object 0xffff888018c7f3e0 (size 16):
  comm "syz-executor.3", pid 10450, jiffies 4295997528 (age 17.649s)
  hex dump (first 16 bytes):
    d0 61 80 44 80 88 ff ff 00 a0 a9 43 80 88 ff ff  .a.D.......C....
  backtrace:
    [<0000000092d587f2>] kmalloc include/linux/slab.h:552 [inline]
    [<0000000092d587f2>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<00000000d213ba1a>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<0000000021785f3e>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<00000000260b7733>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<00000000bb7e80d5>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<0000000033957650>] do_new_mount fs/namespace.c:2881 [inline]
    [<0000000033957650>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<000000007e3f59e6>] do_mount fs/namespace.c:3224 [inline]
    [<000000007e3f59e6>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<000000007e3f59e6>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<000000007e3f59e6>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<00000000272accac>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<000000009b111bd9>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed