BUG: memory leak
unreferenced object 0xffff88805dfb1660 (size 16):
  comm "syz-executor.1", pid 6499, jiffies 4295229887 (age 18.386s)
  hex dump (first 16 bytes):
    70 85 a4 19 80 88 ff ff 00 20 96 44 80 88 ff ff  p........ .D....
  backtrace:
    [<000000008d343a59>] kmalloc include/linux/slab.h:552 [inline]
    [<000000008d343a59>] ext4_multi_mount_protect+0x861/0xb20 fs/ext4/mmp.c:367
    [<0000000029f63b27>] ext4_fill_super+0xa20e/0xcf20 fs/ext4/super.c:4774
    [<000000008b3cf643>] mount_bdev+0x331/0x3f0 fs/super.c:1419
    [<00000000d5ceec14>] legacy_get_tree+0x105/0x220 fs/fs_context.c:592
    [<000000003d2ec10f>] vfs_get_tree+0x8e/0x2f0 fs/super.c:1549
    [<00000000e5ff5694>] do_new_mount fs/namespace.c:2881 [inline]
    [<00000000e5ff5694>] path_mount+0x139a/0x2080 fs/namespace.c:3211
    [<0000000079831cf8>] do_mount fs/namespace.c:3224 [inline]
    [<0000000079831cf8>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<0000000079831cf8>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<0000000079831cf8>] __x64_sys_mount+0x27e/0x300 fs/namespace.c:3409
    [<00000000f2197a25>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
    [<0000000036ad1fd8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: leak checking failed