Given the following code containing errors, provide Common Weakness Enumeration (CWE) identifiers and corresponding messages in JSON format. Each identified weakness should have a unique entry in the JSON array.
    Code: static int send_png_rect(VncState *vs, int x, int y, int w, int h,
                         VncPalette *palette)
{
    png_byte color_type;
    png_structp png_ptr;
    png_infop info_ptr;
    png_colorp png_palette = NULL;
    pixman_image_t *linebuf;
    int level = tight_png_conf[vs->tight.compression].png_zlib_level;
    int filters = tight_png_conf[vs->tight.compression].png_filters;
    uint8_t *buf;
    int dy;

    png_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL,
                                        NULL, vnc_png_malloc, vnc_png_free);

    if (png_ptr == NULL)
        return -1;

    info_ptr = png_create_info_struct(png_ptr);

    if (info_ptr == NULL) {
        png_destroy_write_struct(&png_ptr, NULL);
        return -1;
    }

    png_set_write_fn(png_ptr, (void *) vs, png_write_data, png_flush_data);
    png_set_compression_level(png_ptr, level);
    png_set_filter(png_ptr, PNG_FILTER_TYPE_DEFAULT, filters);

    if (palette) {
        color_type = PNG_COLOR_TYPE_PALETTE;
    } else {
        color_type = PNG_COLOR_TYPE_RGB;
    }

    png_set_IHDR(png_ptr, info_ptr, w, h,
                 8, color_type, PNG_INTERLACE_NONE,
                 PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);

    if (color_type == PNG_COLOR_TYPE_PALETTE) {
        struct palette_cb_priv priv;

        png_palette = png_malloc(png_ptr, sizeof(*png_palette) *
                                 palette_size(palette));

        priv.vs = vs;
        priv.png_palette = png_palette;
        palette_iter(palette, write_png_palette, &priv);

        png_set_PLTE(png_ptr, info_ptr, png_palette, palette_size(palette));

        if (vs->client_pf.bytes_per_pixel == 4) {
            tight_encode_indexed_rect32(vs->tight.tight.buffer, w * h, palette);
        } else {
            tight_encode_indexed_rect16(vs->tight.tight.buffer, w * h, palette);
        }
    }

    png_write_info(png_ptr, info_ptr);

    buffer_reserve(&vs->tight.png, 2048);
    linebuf = qemu_pixman_linebuf_create(PIXMAN_BE_r8g8b8, w);
    buf = (uint8_t *)pixman_image_get_data(linebuf);
    for (dy = 0; dy < h; dy++)
    {
        if (color_type == PNG_COLOR_TYPE_PALETTE) {
            memcpy(buf, vs->tight.tight.buffer + (dy * w), w);
        } else {
            qemu_pixman_linebuf_fill(linebuf, vs->vd->server, w, x, y + dy);
        }
        png_write_row(png_ptr, buf);
    }
    qemu_pixman_image_unref(linebuf);

    png_write_end(png_ptr, NULL);

    if (color_type == PNG_COLOR_TYPE_PALETTE) {
        png_free(png_ptr, png_palette);
    }

    png_destroy_write_struct(&png_ptr, &info_ptr);

    vnc_write_u8(vs, VNC_TIGHT_PNG << 4);

    tight_send_compact_size(vs, vs->tight.png.offset);
    vnc_write(vs, vs->tight.png.buffer, vs->tight.png.offset);
    buffer_reset(&vs->tight.png);
    return 1;
} ; Sample JSON Format Confermily Expected output: "examples" => "cwe": "xxx"; "message": "xxx"
    
 'cwe': ['CWE-401'], 'message': 'vnc: fix memory leak when vnc disconnect

Currently when qemu receives a vnc connect, it creates a 'VncState' to
represent this connection. In 'vnc_worker_thread_loop' it creates a
local 'VncState'. The connection 'VcnState' and local 'VncState' exchange
data in 'vnc_async_encoding_start' and 'vnc_async_encoding_end'.
In 'zrle_compress_data' it calls 'deflateInit2' to allocate the libz library
opaque data. The 'VncState' used in 'zrle_compress_data' is the local
'VncState'. In 'vnc_zrle_clear' it calls 'deflateEnd' to free the libz
library opaque data. The 'VncState' used in 'vnc_zrle_clear' is the connection
'VncState'. In currently implementation there will be a memory leak when the
vnc disconnect. Following is the asan output backtrack:

Direct leak of 29760 byte(s) in 5 object(s) allocated from:
    0 0xffffa67ef3c3 in __interceptor_calloc (/lib64/libasan.so.4+0xd33c3)
    1 0xffffa65071cb in g_malloc0 (/lib64/libglib-2.0.so.0+0x571cb)
    2 0xffffa5e968f7 in deflateInit2_ (/lib64/libz.so.1+0x78f7)
    3 0xaaaacec58613 in zrle_compress_data ui/vnc-enc-zrle.c:87
    4 0xaaaacec58613 in zrle_send_framebuffer_update ui/vnc-enc-zrle.c:344
    5 0xaaaacec34e77 in vnc_send_framebuffer_update ui/vnc.c:919
    6 0xaaaacec5e023 in vnc_worker_thread_loop ui/vnc-jobs.c:271
    7 0xaaaacec5e5e7 in vnc_worker_thread ui/vnc-jobs.c:340
    8 0xaaaacee4d3c3 in qemu_thread_start util/qemu-thread-posix.c:502
    9 0xffffa544e8bb in start_thread (/lib64/libpthread.so.0+0x78bb)
    10 0xffffa53965cb in thread_start (/lib64/libc.so.6+0xd55cb)

This is because the opaque allocated in 'deflateInit2' is not freed in
'deflateEnd'. The reason is that the 'deflateEnd' calls 'deflateStateCheck'
and in the latter will check whether 's->strm != strm'(libz's data structure).
This check will be true so in 'deflateEnd' it just return 'Z_STREAM_ERROR' and
not free the data allocated in 'deflateInit2'.

The reason this happens is that the 'VncState' contains the whole 'VncZrle',
so when calling 'deflateInit2', the 's->strm' will be the local address.
So 's->strm != strm' will be true.

To fix this issue, we need to make 'zrle' of 'VncState' to be a pointer.
Then the connection 'VncState' and local 'VncState' exchange mechanism will
work as expection. The 'tight' of 'VncState' has the same issue, let's also turn
it to a pointer.

Reported-by: Ying Fang <fangying1@huawei.com>
Signed-off-by: Li Qiang <liq3ea@163.com>
Message-id: 20190831153922.121308-1-liq3ea@163.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>'