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| Code Block |
|---|
|
void f1 (size_t nchars, size_t val) {
char *p = (char *)malloc(nchars);
const size_t n = val;
if (nchars - n < 0) {
    /* Handle Error */
}
else {
memset(p, 0, n);
}
/* More program code */
}
|
Noncompliant Code Example
This noncompliant code example assigns a value greater than the size of dynamic memory to 'n' which is then passed to the memset().
| Code Block |
|---|
|
void f2() {
float a[4];
const size_t n= sizeof(int) * 4;
void *p = a;
memset(p, 0, n);
/* More program code */
}
|
Compliant Solution
This compliant solution makes sure that the value of 'n' is not greater the size of the dynamic memory pointed to by the pointer 'p':
| Code Block |
|---|
|
void f2() {
float a[4];
const size_t n= sizeof(float) * 4;
void *p = a;
memset(p, 0, n);
/* More program code */
}
|
Risk Assessment
Depending on the library function called, the attacker may be able to use a heap overflow vulnerability to run arbitrary code. The detection of checks specified in description can be automated but the remediation has to be manual.
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