skip_stream(struct archive_read *a, size_t skip_bytes)
{
	struct _7zip *zip = (struct _7zip *)a->format->data;
	const void *p;
	int64_t skipped_bytes;
	size_t bytes = skip_bytes;

	if (zip->folder_index == 0) {
		/*
		 * Optimization for a list mode.
		 * Avoid unncecessary decoding operations.
		 */
		zip->si.ci.folders[zip->entry->folderIndex].skipped_bytes
		    += skip_bytes;
		return (skip_bytes);
	}

	while (bytes) {
		skipped_bytes = read_stream(a, &p, bytes, 0);
		if (skipped_bytes < 0)
			return (skipped_bytes);
		if (skipped_bytes == 0) {
			archive_set_error(&a->archive,
			    ARCHIVE_ERRNO_FILE_FORMAT,
			    "Truncated 7-Zip file body");
			return (ARCHIVE_FATAL);
		}
		bytes -= (size_t)skipped_bytes;
		if (zip->pack_stream_bytes_unconsumed)
			read_consume(a);
	}
	return (skip_bytes);
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.