Based on the provided code slice and the specified vulnerability types (CWE-476: Null Pointer Dereference and CWE-787: Out-of-bounds Write), the main concern appears to be with the `copy_from_sockptr` function calls. The vulnerability likely stems from potential null pointer dereferences or buffer overflows. Here are five possible patches to address these issues:

Patch 1: Add null pointer check for `sk` before locking
```c
14     if (!sk) return -EINVAL;
15     lock_sock(sk);
```

Patch 2: Validate `optlen` before copying data
```c
24     if (optlen < sizeof(u32)) return -EINVAL;
25     if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
```

Patch 3: Use a safer copy function with size checking
```c
25     if (copy_from_sockptr_safe(&opt, optval, sizeof(u32), optlen)) {
```

Patch 4: Add bounds checking for `optval`
```c
24     if (!access_ok(VERIFY_READ, optval, sizeof(u32))) return -EFAULT;
25     if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
```

Patch 5: Combine null check, optlen validation, and bounds checking
```c
14     if (!sk || optlen < sizeof(u32) || !access_ok(VERIFY_READ, optval, sizeof(u32))) return -EINVAL;
15     lock_sock(sk);
```

These patches aim to prevent null pointer dereferences and ensure that the data being copied is within the bounds of the provided buffer. The same changes should be applied to both instances of `copy_from_sockptr` in the function.