diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 86f38d239476..83a77a445538 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -20,44 +20,48 @@
 #include <linux/device.h>
 #include "tpm.h"
 
-#define READ_PUBEK_RESULT_SIZE 314
+struct tpm_readpubek_out {
+	u8 algorithm[4];
+	u8 encscheme[2];
+	u8 sigscheme[2];
+	__be32 paramsize;
+	u8 parameters[12];
+	__be32 keysize;
+	u8 modulus[256];
+	u8 checksum[20];
+} __packed;
+
 #define READ_PUBEK_RESULT_MIN_BODY_SIZE (28 + 256)
 #define TPM_ORD_READPUBEK 124
-static const struct tpm_input_header tpm_readpubek_header = {
-	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
-	.length = cpu_to_be32(30),
-	.ordinal = cpu_to_be32(TPM_ORD_READPUBEK)
-};
+
 static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
-	u8 *data;
-	struct tpm_cmd_t tpm_cmd;
-	ssize_t err;
-	int i, rc;
+	struct tpm_buf tpm_buf;
+	struct tpm_readpubek_out *out;
+	ssize_t rc;
+	int i;
 	char *str = buf;
 	struct tpm_chip *chip = to_tpm_chip(dev);
+	char anti_replay[20];
 
-	memset(&tpm_cmd, 0, sizeof(tpm_cmd));
+	memset(&anti_replay, 0, sizeof(anti_replay));
 
-	tpm_cmd.header.in = tpm_readpubek_header;
-	err = tpm_transmit_cmd(chip, NULL, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
-			       READ_PUBEK_RESULT_MIN_BODY_SIZE, 0,
-			       "attempting to read the PUBEK");
-	if (err)
-		goto out;
+	rc = tpm_buf_init(&tpm_buf, TPM_TAG_RQU_COMMAND, TPM_ORD_READPUBEK);
+	if (rc)
+		return rc;
 
-	/*
-	   ignore header 10 bytes
-	   algorithm 32 bits (1 == RSA )
-	   encscheme 16 bits
-	   sigscheme 16 bits
-	   parameters (RSA 12->bytes: keybit, #primes, expbit)
-	   keylenbytes 32 bits
-	   256 byte modulus
-	   ignore checksum 20 bytes
-	 */
-	data = tpm_cmd.params.readpubek_out_buffer;
+	tpm_buf_append(&tpm_buf, anti_replay, sizeof(anti_replay));
+
+	rc = tpm_transmit_cmd(chip, NULL, tpm_buf.data, PAGE_SIZE,
+			      READ_PUBEK_RESULT_MIN_BODY_SIZE, 0,
+			      "attempting to read the PUBEK");
+	if (rc) {
+		tpm_buf_destroy(&tpm_buf);
+		return 0;
+	}
+
+	out = (struct tpm_readpubek_out *)&tpm_buf.data[10];
 	str +=
 	    sprintf(str,
 		    "Algorithm: %02X %02X %02X %02X\n"
@@ -68,21 +72,26 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
 		    "%02X %02X %02X %02X\n"
 		    "Modulus length: %d\n"
 		    "Modulus:\n",
-		    data[0], data[1], data[2], data[3],
-		    data[4], data[5],
-		    data[6], data[7],
-		    data[12], data[13], data[14], data[15],
-		    data[16], data[17], data[18], data[19],
-		    data[20], data[21], data[22], data[23],
-		    be32_to_cpu(*((__be32 *) (data + 24))));
+		    out->algorithm[0], out->algorithm[1], out->algorithm[2],
+		    out->algorithm[3],
+		    out->encscheme[0], out->encscheme[1],
+		    out->sigscheme[0], out->sigscheme[1],
+		    out->parameters[0], out->parameters[1],
+		    out->parameters[2], out->parameters[3],
+		    out->parameters[4], out->parameters[5],
+		    out->parameters[6], out->parameters[7],
+		    out->parameters[8], out->parameters[9],
+		    out->parameters[10], out->parameters[11],
+		    be32_to_cpu(out->keysize));
 
 	for (i = 0; i < 256; i++) {
-		str += sprintf(str, "%02X ", data[i + 28]);
+		str += sprintf(str, "%02X ", out->modulus[i]);
 		if ((i + 1) % 16 == 0)
 			str += sprintf(str, "\n");
 	}
-out:
+
 	rc = str - buf;
+	tpm_buf_destroy(&tpm_buf);
 	return rc;
 }
 static DEVICE_ATTR_RO(pubek);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 2d5466a72e40..b50e92fbca31 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -345,17 +345,6 @@ enum tpm_sub_capabilities {
 	TPM_CAP_PROP_TIS_DURATION = 0x120,
 };
 
-struct	tpm_readpubek_params_out {
-	u8	algorithm[4];
-	u8	encscheme[2];
-	u8	sigscheme[2];
-	__be32	paramsize;
-	u8	parameters[12]; /*assuming RSA*/
-	__be32	keysize;
-	u8	modulus[256];
-	u8	checksum[20];
-} __packed;
-
 typedef union {
 	struct	tpm_input_header in;
 	struct	tpm_output_header out;
@@ -385,8 +374,6 @@ struct tpm_getrandom_in {
 } __packed;
 
 typedef union {
-	struct	tpm_readpubek_params_out readpubek_out;
-	u8	readpubek_out_buffer[sizeof(struct tpm_readpubek_params_out)];
 	struct	tpm_pcrread_in	pcrread_in;
 	struct	tpm_pcrread_out	pcrread_out;
 	struct	tpm_getrandom_in getrandom_in;