...
The signal handler may also call a handful of functions, including abort(). (See SIG30-C. Call only asynchronous-safe functions within signal handlers for details of functions that can be safely called from within signal handlers.)
...
Noncompliant Code Example
In this non-compliant noncompliant code example, err_msg is updated to indicate that the SIGINT signal was delivered. Undefined behavior occurs if a SIGINT is generated before the allocation completes.
...