BUG: memory leak
unreferenced object 0xffff888046b54360 (size 16):
  comm "syz-executor.3", pid 29789, jiffies 4296173413 (age 19.358s)
  hex dump (first 16 bytes):
    88 e4 49 49 80 88 ff ff 00 80 56 3f 80 88 ff ff  ..II......V?....
  backtrace:
    [<00000000150831ff>] kmalloc include/linux/slab.h:552 [inline]
    [<00000000150831ff>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<000000001e3d4fce>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<00000000b061bdad>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<0000000002a9dd1f>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<0000000094f662f9>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<0000000047a52f5a>] do_new_mount fs/namespace.c:2881 [inline]
    [<0000000047a52f5a>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<00000000363c58d4>] do_mount fs/namespace.c:3224 [inline]
    [<00000000363c58d4>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<00000000363c58d4>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<00000000363c58d4>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<00000000768f9121>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<000000004158f271>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed