BUG: memory leak
unreferenced object 0xffff888008ceb760 (size 16):
  comm "syz-executor.3", pid 26833, jiffies 4296814744 (age 19.515s)
  hex dump (first 16 bytes):
    e8 b0 d9 40 80 88 ff ff 00 20 ba 50 80 88 ff ff  ...@..... .P....
  backtrace:
    [<00000000d951d33f>] kmalloc include/linux/slab.h:552 [inline]
    [<00000000d951d33f>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<000000009495b12a>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<0000000011379371>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<00000000575c7b66>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<000000007a00d6f5>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<000000000d8b7547>] do_new_mount fs/namespace.c:2881 [inline]
    [<000000000d8b7547>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<000000001593a706>] do_mount fs/namespace.c:3224 [inline]
    [<000000001593a706>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<000000001593a706>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<000000001593a706>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<0000000098c3f1d5>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<000000006e3d8c8a>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed