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IAR Embedded Workbench for RH850 3.20.x

CERT-EXP33-C_d

In this section:
Synopsis

Do not read uninitialized memory.

Enabled by default

Yes

Severity/Certainty

High/Medium

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Full description

Uninitialized automatic variables or dynamically allocated memory has indeterminate values, which for objects of some types, can be a trap representation. Reading such trap representations is undefined behavior; it can cause a program to behave in an unexpected manner and provide an avenue for attack. This check is identical to MISRAC2004-1.2_a, MISRAC2012-Rule-9.1_b, SPC-uninit-arr-all.

Coding standards
CERT EXP33-C

Do not reference uninitialized memory

CWE 758

Reliance on Undefined, Unspecified, or Implementation-Defined Behavior

CWE 824

Access of Uninitialized Pointer

CWE 908

Use of Uninitialized Resource

MISRA C:2004 1.2

(Required) No reliance shall be placed on undefined or unspecified behavior.

MISRA C:2012 Rule-9.1

(Mandatory) The value of an object with automatic storage duration shall not be read before it has been set

Code examples

The following code example fails the check and will give a warning:

void example() {
  int a[20];
  int b = a[1];
}

The following code example passes the check and will not give a warning about this issue:

extern void f(int*);
void example() {
  int a[20];
  f(a);
  int b = a[1];
}