BUG: memory leak
unreferenced object 0xffff888123e35360 (size 32):
  comm "syz-executor.3", pid 11832, jiffies 4294986796 (age 9.670s)
  hex dump (first 32 bytes):
    70 22 2e 14 81 88 ff ff 00 d0 2a 23 81 88 ff ff  p"........*#....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000c127498b>] kmalloc include/linux/slab.h:552 [inline]
    [<00000000c127498b>] ext4_multi_mount_protect+0x4a6/0x5d0 fs/ext4/mmp.c:367
    [<00000000c9af9295>] ext4_fill_super+0x5650/0x5ad0 fs/ext4/super.c:4768
    [<000000005178254d>] mount_bdev+0x223/0x260 fs/super.c:1366
    [<000000000995d660>] legacy_get_tree+0x2b/0x90 fs/fs_context.c:592
    [<00000000ddc89f8a>] vfs_get_tree+0x28/0x100 fs/super.c:1496
    [<000000009af180f1>] do_new_mount fs/namespace.c:2881 [inline]
    [<000000009af180f1>] path_mount+0xc5e/0x1170 fs/namespace.c:3211
    [<000000004d87799c>] do_mount fs/namespace.c:3224 [inline]
    [<000000004d87799c>] __do_sys_mount fs/namespace.c:3432 [inline]
    [<000000004d87799c>] __se_sys_mount fs/namespace.c:3409 [inline]
    [<000000004d87799c>] __x64_sys_mount+0x18e/0x1d0 fs/namespace.c:3409
    [<000000008be715a9>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<0000000012d98ed7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9