Q: Given the following code slice:
```
1 int
2 nvkm_firmware_ctor(const struct nvkm_firmware_func *func, const char *name,
3 		   struct nvkm_device *device, const void *src, int len, struct nvkm_firmware *fw)
4 {
5 	fw->func = func;
6 	fw->name = name;
7 	fw->device = device;
8 	fw->len = len;
9 
10 	switch (fw->func->type) {
11 	case NVKM_FIRMWARE_IMG_RAM:
12 		fw->img = kmemdup(src, fw->len, GFP_KERNEL);
13 		break;
14 	case NVKM_FIRMWARE_IMG_DMA: {
15 		len = ALIGN(fw->len, PAGE_SIZE);
16 
17 		fw->img = kmalloc(len, GFP_KERNEL);
18 		if (!fw->img)
19 			return -ENOMEM;
20 
21 		memcpy(fw->img, src, fw->len);
22 		fw->phys = dma_map_single(fw->device->dev, fw->img, len, DMA_TO_DEVICE);
23 		if (dma_mapping_error(fw->device->dev, fw->phys)) {
24 			kfree(fw->img);
25 			return -EFAULT;
26 		}
27 
28 		sg_init_one(&fw->mem.sgl, fw->img, len);
29 		sg_dma_address(&fw->mem.sgl) = fw->phys;
30 		sg_dma_len(&fw->mem.sgl) = len;
31 	}
32 		break;
33 	default:
34 		WARN_ON(1);
35 		return -EINVAL;
36 	}
37 
38 	if (!fw->img)
39 		return -ENOMEM;
40 
41 	nvkm_memory_ctor(&nvkm_firmware_mem, &fw->mem.memory);
42 	return 0;
43 }
```
which has a vulnerability among CWE-416,CWE-476,CWE-787,CWE-125 and among lines:
```
15 		len = ALIGN(fw->len, PAGE_SIZE);
21 		memcpy(fw->img, src, fw->len);
24 			kfree(fw->img);
28 		sg_init_one(&fw->mem.sgl, fw->img, len);
34 		WARN_ON(1);
```
Please generate five possible patches for the vulnerability.