Language: C
Label: safe
CWE: CWE-362 \u2014 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.

Code:
static inline bool _arq_scheduled(gnrc_sixlowpan_frag_fb_t *fbuf)
{
    evtimer_event_t *ptr = _arq_timer.events;
    evtimer_event_t *event = &fbuf->sfr.arq_timeout_event.event;
    while (ptr) {
        if (ptr == event) {
            return true;
        }
        ptr = ptr->next;
    }
    return false;
}