According to C99 \[[ISO/IEC 9899-1999|AA. C References#ISO/IEC 9899-1999]\] Section 6.7.3, "Type qualifiers," Paragraph 5:

If an attempt is made to refer to an object defined with a volatile-qualified type through use of an lvalue with non-volatile-qualified type, the behavior is undefined.

This also applies to objects that behave as if they were defined with qualified types, such as an object at a memory-mapped input/output address.

Risk Assessment

Accessing a volatile object through a non-volatile reference can result in undefined and perhaps unintended program behavior.

Rule

Severity

Likelihood

Remediation Cost

Priority

Level

EXP32-C

1 (low)

3 (likely)

2 (medium)

P6

L2

Related Vulnerabilities

Search for vulnerabilities resulting from the violation of this rule on the CERT website.

References

\[[ISO/IEC 9899-1999|AA. C References#ISO/IEC 9899-1999]\] Section 6.7.3, "Type qualifiers," and Section 6.5.16.1, "Simple assignment"
\[[ISO/IEC PDTR 24772|AA. C References#ISO/IEC PDTR 24772]\] "HFC Pointer casting and pointer type changes"
\[[MISRA 04|AA. C References#MISRA 04]\] Rule 11.5

EXP31-C. Do not modify constant values      03. Expressions (EXP)       EXP33-C. Do not reference uninitialized variables