BUG: memory leak
unreferenced object 0xffff88803f5bc8c0 (size 16):
  comm "syz-executor.3", pid 19299, jiffies 4296130415 (age 17.310s)
  hex dump (first 16 bytes):
    80 6e 60 19 80 88 ff ff 00 e0 54 3e 80 88 ff ff  .n`.......T>....
  backtrace:
    [<00000000f9b59165>] kmalloc include/linux/slab.h:552 [inline]
    [<00000000f9b59165>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<00000000d74a25aa>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<0000000019c58795>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<0000000019527004>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<000000004d1e8153>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<00000000fe0d0625>] do_new_mount fs/namespace.c:2881 [inline]
    [<00000000fe0d0625>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<0000000054f63049>] do_mount fs/namespace.c:3224 [inline]
    [<0000000054f63049>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<0000000054f63049>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<0000000054f63049>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<00000000a3c283b0>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<0000000073ddbc86>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed