static void drop_futex_key_refs(union futex_key *key)
{
	if (!key->both.ptr) {
		/* If we're here then we tried to put a key we failed to get */
		WARN_ON_ONCE(1);
		return;
	}

	if (!IS_ENABLED(CONFIG_MMU))
		return;

	switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
	case FUT_OFF_INODE:
		iput(key->shared.inode);
		break;
	case FUT_OFF_MMSHARED:
		mmdrop(key->private.mm);
		break;
	}
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.