BUG: memory leak
unreferenced object 0xffff888015381e80 (size 16):
  comm "syz-executor.5", pid 8492, jiffies 4295433652 (age 27.252s)
  hex dump (first 16 bytes):
    10 a9 9b 20 80 88 ff ff 00 40 b0 45 80 88 ff ff  ... .....@.E....
  backtrace:
    [<00000000b68eabe4>] kmalloc include/linux/slab.h:552 [inline]
    [<00000000b68eabe4>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<00000000a42bb83b>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<0000000022ffc03a>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<000000003be9582e>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<000000001fa3e77b>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<00000000f4163161>] do_new_mount fs/namespace.c:2881 [inline]
    [<00000000f4163161>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<0000000056c3978c>] do_mount fs/namespace.c:3224 [inline]
    [<0000000056c3978c>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<0000000056c3978c>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<0000000056c3978c>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<000000008ce415d6>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<0000000082651b12>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed