static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
			unsigned int key_len)
{
	struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);
	int i, j = 0, k = 0;

	ctx->x = 1;
	ctx->y = 0;

	for (i = 0; i < 256; i++)
		ctx->S[i] = i;

	for (i = 0; i < 256; i++) {
		u32 a = ctx->S[i];
		j = (j + in_key[k] + a) & 0xff;
		ctx->S[i] = ctx->S[j];
		ctx->S[j] = a;
		if (++k >= key_len)
			k = 0;
	}

	return 0;
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.