Traditional Static Allocation Policy (DYN02)

Level \(\rightarrow\) Advisory

Category

Safety:

\(\checkmark\)

Cyber:

\(\checkmark\)

Goal

Maintainability:

\(\checkmark\)

Reliability:

\(\checkmark\)

Portability:

Performance:

Security:

\(\checkmark\)

Remediation \(\rightarrow\) Low

Verification Method \(\rightarrow\) Compiler restrictions

Reference

MISRA C Dir 4.12: "Dynamic memory allocation shall not be used."

Description

The following restrictions must be in effect:

• No_Allocators

• No_Task_Allocators

Under the traditional approach, no dynamic allocations and no deallocations occur. Only declared objects are used and no access types of any kind appear in the code.

Without allocations there is no issue with deallocation as there would be nothing to deallocate. Heap storage exhaustion and fragmentation are clearly prevented although storage may still be exhausted due to insufficient stack size allotments.

In this approach the following constructs are not allowed:

• Allocators

• Access-to-constant access types

• Access-to-variable access types

• User-defined storage pools

• Unchecked Deallocations

Applicable Vulnerability within ISO TR 24772-2

• 4.10 Storage Pool

Applicable Common Weakness Enumeration

• CWE-401 - Missing Release of Memory after Effective Lifetime

• CWE-758 - Reliance on Undefined, Unspecified, or Implementation-Defined Behavior

• CWE-771 - Missing Reference to Active Allocated Resource

• CWE-1325 - Improperly Controlled Sequential Memory Allocation

Noncompliant Code Example

Any code using the constructs listed above.

Compliant Code Example

N/A

Notes

The compiler, and/or GNATcheck, will detect violations of the restrictions.