To generate the patch for the given code slice with a CWE-787 vulnerability, we can follow these reasoning steps:

### Step 1: Root Cause Analysis

- 1: Validate Memory Allocation:
  - The code allocates memory using `kmalloc` for `SZ_SG_REQ_INFO * SG_MAX_QUEUE` bytes.
  - The allocated memory is not initialized, which means it may contain arbitrary values.

- 2: Potential Vulnerability:
  - The vulnerability arises because the allocated memory is not initialized, and it is used to store sensitive information (`sg_req_info_t` struct).
  - If the allocated memory contains arbitrary values, it may lead to unexpected behavior or crashes when the program tries to access or use the memory.

- 3: CWE-787 Vulnerability:
  - CWE-787 is an out-of-bounds write vulnerability, which occurs when a program writes data to a memory location outside the intended buffer.
  - In this case, the vulnerability is not directly related to out-of-bounds write, but rather to the lack of initialization of the allocated memory.

### Conclusion:
The vulnerable behavior in this code is due to the lack of initialization of the allocated memory. The `kmalloc` function allocates memory but does not initialize it, which may lead to unexpected behavior or crashes when the program tries to access or use the memory.

### Step 2: Fixing Strategy

- A common fixing strategy for this type of vulnerability is to use a memory allocation function that initializes the allocated memory to zero.
- In the Linux kernel, the `kzalloc` function is used to allocate memory and initialize it to zero.
- By replacing `kmalloc` with `kzalloc`, we can ensure that the allocated memory is initialized to zero, which prevents the vulnerability.

### Patch:
```
<             rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE, GFP_KERNEL);
---
>             rinfo = kzalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE, GFP_KERNEL);
```
Note that the patch is not directly related to fixing an out-of-bounds write vulnerability, but rather to initializing the allocated memory to prevent unexpected behavior or crashes.