BUG: memory leak
unreferenced object 0xffff88800df719a0 (size 16):
  comm "syz-executor.0", pid 8756, jiffies 4295655169 (age 19.256s)
  hex dump (first 16 bytes):
    40 27 b9 20 80 88 ff ff 00 a0 71 46 80 88 ff ff  @'. ......qF....
  backtrace:
    [<000000001d1b0c87>] kmalloc include/linux/slab.h:552 [inline]
    [<000000001d1b0c87>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<000000007b91cd36>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<00000000a6516632>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<000000006367bf28>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<000000000ec3f84a>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<0000000047055560>] do_new_mount fs/namespace.c:2881 [inline]
    [<0000000047055560>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<00000000ac7c6852>] do_mount fs/namespace.c:3224 [inline]
    [<00000000ac7c6852>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<00000000ac7c6852>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<00000000ac7c6852>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<00000000f89d4391>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<00000000354cb9f2>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed