BUG: memory leak
unreferenced object 0xffff88803a7cad60 (size 16):
  comm "syz-executor.6", pid 19999, jiffies 4297859891 (age 22.142s)
  hex dump (first 16 bytes):
    98 fd b8 20 80 88 ff ff 00 80 0c 18 80 88 ff ff  ... ............
  backtrace:
    [<00000000a07f08c3>] kmalloc include/linux/slab.h:552 [inline]
    [<00000000a07f08c3>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<00000000403bc43b>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<00000000ab01f1a7>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<0000000028721983>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<00000000576b1c80>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<00000000f8455172>] do_new_mount fs/namespace.c:2881 [inline]
    [<00000000f8455172>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<000000008cb10edf>] do_mount fs/namespace.c:3224 [inline]
    [<000000008cb10edf>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<000000008cb10edf>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<000000008cb10edf>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<00000000001d9084>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<000000006cba02ed>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed