To generate this patch, we can follow these reasoning steps:

Step 1. Root Cause Analysis:

1. Input analysis:
   - The function takes `cmnd->cmd_len` as input to calculate `len`.
   - `len` is used to allocate memory for `iu`.

2. Vulnerability identification:
   - The vulnerability is at line 18, where `kmalloc` is used to allocate memory.
   - `kmalloc` allocates uninitialized memory, which can lead to information leakage if not properly handled.

3. Potential issues:
   - If the allocated memory is not fully initialized before use, it may contain residual data from previous allocations.
   - This residual data could potentially be sensitive information, leading to information disclosure vulnerabilities.

4. CWE-787 (Out-of-bounds Write) connection:
   - While the primary issue here is not an out-of-bounds write, uninitialized memory can lead to unexpected behavior if accessed or written to without proper initialization.

Step 2. Fixing Strategy:

1. Identify the core issue:
   - The main problem is the use of `kmalloc`, which doesn't initialize the allocated memory.

2. Consider alternatives:
   - `kzalloc` is a safer alternative to `kmalloc` as it zero-initializes the allocated memory.
   - Using `kzalloc` ensures that no residual data remains in the allocated memory.

3. Propose the fix:
   - Replace `kmalloc` with `kzalloc` to automatically initialize the allocated memory to zero.

4. Verify the fix:
   - `kzalloc` has the same function signature as `kmalloc`, so it can be used as a drop-in replacement.
   - This change doesn't affect the size of the allocation or the error handling, maintaining the original logic.

Therefore, the appropriate patch is to replace `kmalloc` with `kzalloc`:

```
<     iu = kmalloc(sizeof(*iu) + len, gfp);
---
>     iu = kzalloc(sizeof(*iu) + len, gfp);
```

This patch addresses the potential information leakage vulnerability by ensuring that the allocated memory is always initialized, preventing any unintended disclosure of previous memory contents.