Q: Given the following code slice:
```
1 int av_hwframe_ctx_init(AVBufferRef *ref)
2 {
3     AVHWFramesContext *ctx = (AVHWFramesContext*)ref->data;
4     const enum AVPixelFormat *pix_fmt;
5     int ret;
6 
7     if (ctx->internal->source_frames) {
8         /* A derived frame context is already initialised. */
9         return 0;
10     }
11 
12     /* validate the pixel format */
13     for (pix_fmt = ctx->internal->hw_type->pix_fmts; *pix_fmt != AV_PIX_FMT_NONE; pix_fmt++) {
14         if (*pix_fmt == ctx->format)
15             break;
16     }
17     if (*pix_fmt == AV_PIX_FMT_NONE) {
18         av_log(ctx, AV_LOG_ERROR,
19                "The hardware pixel format '%s' is not supported by the device type '%s'\n",
20                av_get_pix_fmt_name(ctx->format), ctx->internal->hw_type->name);
21         return AVERROR(ENOSYS);
22     }
23 
24     /* validate the dimensions */
25     ret = av_image_check_size(ctx->width, ctx->height, 0, ctx);
26     if (ret < 0)
27         return ret;
28 
29     /* format-specific init */
30     if (ctx->internal->hw_type->frames_init) {
31         ret = ctx->internal->hw_type->frames_init(ctx);
32         if (ret < 0)
33             goto fail;
34     }
35 
36     if (ctx->internal->pool_internal && !ctx->pool)
37         ctx->pool = ctx->internal->pool_internal;
38 
39     /* preallocate the frames in the pool, if requested */
40     if (ctx->initial_pool_size > 0) {
41         ret = hwframe_pool_prealloc(ref);
42         if (ret < 0)
43             goto fail;
44     }
45 
46     return 0;
47 fail:
48     if (ctx->internal->hw_type->frames_uninit)
49         ctx->internal->hw_type->frames_uninit(ctx);
50     return ret;
51 }
```
which has a vulnerability among CWE-476 and among lines:
```
20                av_get_pix_fmt_name(ctx->format), ctx->internal->hw_type->name);
```
Please generate five possible patches for the vulnerability.