[metadata]
id = "ERR32-C"
type = "rule"
category = "ERR"
number = 32
title = "Do not rely on indeterminate values of errno"
description = """
According to the C Standard Annex J.2 (133) [ISO/IEC 9899:2024], the behavior of
a program isundefinedwhen Seeundefined behavior 133. A signal handler is allowed
to callsignal();if that fails,signal()returnsSIG_ERRand setserrnoto a positive
value. However, if the event that caused a signal was external (not the result
of the program callingabort()orraise()), the only functions the signal handler
may call are_Exit()orabort(), or it may callsignal()on the signal currently
being handled; ifsignal()fails, the value oferrnoisindeterminate.
"""
severity = "Low"
likelihood = "Unlikely"
priority = "P3"
level = "L3"
cert_version = "2016 Edition (Wiki)"
last_modified = "Oct 29, 2025"
[rules.cert_c.ERR32-C]
enabled = true
[references]
wiki = "https://wiki.sei.cmu.edu/confluence/display/c/ERR32-C.+Do+not+rely+on+indeterminate+values+of+errno"