void alloc_intr_gate(unsigned int n, const void *addr)
{
	BUG_ON(n < FIRST_SYSTEM_VECTOR);
	if (!test_and_set_bit(n, system_vectors))
		set_intr_gate(n, addr);
}

The product contains a concurrent code sequence that 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 operating concurrently.