I'll provide the reasoning steps for generating this patch following the two-step process:

Step 1. Root Cause Analysis:

1. Memory Allocation:
   - The code uses `kmalloc` to allocate memory for an array of `crypto_skcipher *` pointers.
   - The size of the allocation is `cc->tfms_count * sizeof(crypto_skcipher *)`.

2. Potential Issues:
   - `kmalloc` allocates memory but does not initialize it. This means the allocated memory contains whatever data was previously there.
   - If `cc->tfms` is later used without proper initialization, it could lead to use of uninitialized memory.

3. Vulnerability:
   - The CWE-787 (Out-of-bounds Write) vulnerability suggests that there's a risk of writing beyond the allocated buffer.
   - In this case, the vulnerability isn't directly caused by the allocation itself, but by the potential misuse of uninitialized memory.
   - Uninitialized pointers in `cc->tfms` could be interpreted as valid memory addresses, leading to writes to arbitrary memory locations.

Conclusion:
The vulnerability arises from the use of `kmalloc`, which doesn't initialize the allocated memory. This can lead to undefined behavior and potential security issues if the memory is used before being properly initialized.

Step 2. Fixing Strategy:

1. Identify the core issue:
   - The main problem is that the allocated memory is not initialized.

2. Choose an appropriate solution:
   - To fix this, we need to ensure that the allocated memory is initialized to a known state (typically zero).
   - In the Linux kernel, `kzalloc` is a function that allocates memory and initializes it to zero.

3. Apply the fix:
   - Replace `kmalloc` with `kzalloc`.
   - `kzalloc` takes the same arguments as `kmalloc`, so no other changes are needed.

Therefore, the patch is:
```
<     cc->tfms = kmalloc(cc->tfms_count * sizeof(crypto_skcipher *), GFP_KERNEL);
---
>     cc->tfms = kzalloc(cc->tfms_count * sizeof(crypto_skcipher *), GFP_KERNEL);
```

This patch ensures that the allocated memory is initialized to zero, preventing potential issues related to uninitialized memory use and reducing the risk of out-of-bounds writes due to misinterpreted pointer values.