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This noncompliant code example reads data from a file stream into a data structure.:

Code Block

bgColor	#FFCCCC
lang	c

struct myData {
  char c;
  long l;
};

/* ... */

FILE *file;
struct myData data;

/* initializeInitialize file */

if (fread(&data, sizeof(struct myData), 1, file) < sizeof(struct myData)) {
  /* Handle error */
}

...

The best solution is to use either a text representation or a special library that ensures data integrity.:

Code Block

bgColor	#ccccff
lang	c

struct myData {
  char c;
  long l;
};

/* ... */

FILE *file;
struct myData data;
char buf[25];
char *end_ptr;

/* initializeInitialize file */

if (fgets(buf, 1, file) == NULL) {
  /* Handle error */
}

data.c = buf[0];

if (fgets(buf, sizeof(buf), file) == NULL) {
  /* Handle Error */
}

data.l = strtol(buf, &end_ptr, 10);

if ((ERANGE == errno)
 || (end_ptr == buf)
 || ('\n' != *end_ptr && '\0' != *end_ptr)) {
    /* Handle Error */
}

...

Reading binary data that has a different format than expected may result in unintended program behavior.

Recommendation	Severity	Likelihood	Detectable

Remediation Cost

Repairable	Priority	Level
FIO09-C

medium

Medium

Probable

probable

No

high

No

P4

L3

Automated Detection

Tool	Version	Checker	Description
Compass/ROSE

Could flag possible violations of this rule by noting any pointer to struct that is passed to fread(), as the noncompliant code example demonstrates

.

LDRA tool suite

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