Mitigate Baron SameEdit (CVE-2021-3156) vulnerability

sles 15.2
integer weakness #49

2

Weakness Breakdown


Definition:

An integer overflow occurs when the answer to an arithmetic operation exceeds the maximum size of the integer type used to store it. The resulting value will appear to have wrapped around the maximum value and started again at the minimum value. This would look like a clock that represents 13:00 by pointing at 1:00. An attacker can use an integer overflow during a buffer length calculation, which results in the allocated buffer being too small to hold the data copied into it, thus causing a buffer overflow.

Warning code(s):

Unless checked, the resulting number can exceed the expected range.

File Name:

libblockdev-2.22/src/plugins/part.c

Context:

The highlighted line of code below is the trigger point of this particular Sles 15.2 integer weakness.

     gboolean success = FALSE;
    guint64 progress_id = 0;
    gchar *msg = NULL;

    if (!check_deps (&avail_deps, DEPS_SGDISK_MASK, deps, DEPS_LAST, &deps_check_lock, error))
        return FALSE;

    msg = g_strdup_printf ("Started setting type on the partition '%s'", part);
    progress_id = bd_utils_report_started (msg);
    g_free (msg);

    if (!part || (part && (*part == '\0'))) {
        g_set_error (error, BD_PART_ERROR, BD_PART_ERROR_INVAL,
                     "Invalid partition path given: '%s'", part);
        bd_utils_report_finished (progress_id, (*error)->message);
        return FALSE;
    }

    part_num_str = part + (strlen (part) - 1);
    while (isdigit (*part_num_str) || (*part_num_str == '-')) {
        part_num_str--;
    }
    part_num_str++;

    if ((g_strcmp0 (part_num_str, "0") != 0) && (atoi (part_num_str) == 0)) {
        g_set_error (error, BD_PART_ERROR, BD_PART_ERROR_INVAL,
                     "Invalid partition path given: '%s'. Cannot extract partition number", part);
        bd_utils_report_finished (progress_id, (*error)->message);
        return FALSE;
    }

    args[2] = g_strdup_printf ("%s:%s", part_num_str, type_guid);

    success = bd_utils_exec_and_report_error (args, NULL, error);
    g_free ((gchar*) args[2]);

    bd_utils_report_finished (progress_id, "Completed");

    return success;
}

/**
 * bd_part_set_part_id:
 * @disk: device the partition belongs to
 * @part: partition the should be set for
 * @part_id: partition Id
 * @error: (out): place to store error (if any)
 *
 * Returns: whether the @part_id type was successfully set for @part or not
 * 

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