static int kempf_decode_tile(G2MContext *c, int tile_x, int tile_y,
                             const uint8_t *src, int src_size)
{
    int width, height;
    int hdr, zsize, npal, tidx = -1, ret;
    int i, j;
    const uint8_t *src_end = src + src_size;
    uint8_t pal[768], transp[3];
    uLongf dlen = (c->tile_width + 1) * c->tile_height;
    int sub_type;
    int nblocks, cblocks, bstride;
    int bits, bitbuf, coded;
    uint8_t *dst = c->framebuf + tile_x * c->tile_width * 3 +
                   tile_y * c->tile_height * c->framebuf_stride;

    if (src_size < 2)
        return AVERROR_INVALIDDATA;

    width  = FFMIN(c->width  - tile_x * c->tile_width,  c->tile_width);
    height = FFMIN(c->height - tile_y * c->tile_height, c->tile_height);

    hdr = *src++;
    sub_type = hdr >> 5;
    if (sub_type == 0) {
        int j;
        memcpy(transp, src, 3);
        src += 3;
        for (j = 0; j < height; j++, dst += c->framebuf_stride)
            for (i = 0; i < width; i++)
                memcpy(dst + i * 3, transp, 3);
        return 0;
    } else if (sub_type == 1) {
        return jpg_decode_data(&c->jc, width, height, src, src_end - src,
                               dst, c->framebuf_stride, NULL, 0, 0, 0);
    }

    if (sub_type != 2) {
        memcpy(transp, src, 3);
        src += 3;
    }
    npal = *src++ + 1;
    memcpy(pal, src, npal * 3); src += npal * 3;
    if (sub_type != 2) {
        for (i = 0; i < npal; i++) {
            if (!memcmp(pal + i * 3, transp, 3)) {
               tidx = i;
               break;
            }
        }
    }

    if (src_end - src < 2)
         return 0;
     zsize = (src[0] << 8) | src[1]; src += 2;
 
    if (src_end - src < zsize + (sub_type != 2))
         return AVERROR_INVALIDDATA;
 
     ret = uncompress(c->kempf_buf, &dlen, src, zsize);
    if (ret)
        return AVERROR_INVALIDDATA;
    src += zsize;

    if (sub_type == 2) {
        kempf_restore_buf(c->kempf_buf, dlen, dst, c->framebuf_stride,
                          NULL, 0, width, height, pal, npal, tidx);
        return 0;
    }

    nblocks = *src++ + 1;
    cblocks = 0;
    bstride = FFALIGN(width, 16) >> 4;
    bits = 0;
     for (i = 0; i < (FFALIGN(height, 16) >> 4); i++) {
         for (j = 0; j < (FFALIGN(width, 16) >> 4); j++) {
             if (!bits) {
                if (src >= src_end)
                    return AVERROR_INVALIDDATA;
                 bitbuf = *src++;
                 bits   = 8;
             }
            coded = bitbuf & 1;
            bits--;
            bitbuf >>= 1;
            cblocks += coded;
            if (cblocks > nblocks)
                return AVERROR_INVALIDDATA;
            c->kempf_flags[j + i * bstride] = coded;
        }
    }

    memset(c->jpeg_tile, 0, c->tile_stride * height);
    jpg_decode_data(&c->jc, width, height, src, src_end - src,
                    c->jpeg_tile, c->tile_stride,
                    c->kempf_flags, bstride, nblocks, 0);

    kempf_restore_buf(c->kempf_buf, dlen, dst, c->framebuf_stride,
                      c->jpeg_tile, c->tile_stride,
                      width, height, pal, npal, tidx);

    return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.