tpm: Check size of response before accessing data
Make sure that we have not received less bytes than what is indicated
in the header of the TPM response. Also, check the number of bytes in
the response before accessing its data.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 6eda239..a0199f1 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -248,6 +248,9 @@
(sizeof(struct tpm_input_header) + \
sizeof(struct tpm2_pcr_read_in))
+#define TPM2_PCR_READ_RESP_BODY_SIZE \
+ sizeof(struct tpm2_pcr_read_out)
+
static const struct tpm_input_header tpm2_pcrread_header = {
.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
.length = cpu_to_be32(TPM2_PCR_READ_IN_SIZE),
@@ -280,8 +283,9 @@
sizeof(cmd.params.pcrread_in.pcr_select));
cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
- rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
- "attempting to read a pcr value");
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ TPM2_PCR_READ_RESP_BODY_SIZE,
+ 0, "attempting to read a pcr value");
if (rc == 0) {
buf = cmd.params.pcrread_out.digest;
memcpy(res_buf, buf, TPM_DIGEST_SIZE);
@@ -327,7 +331,7 @@
cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE);
- rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, 0,
"attempting extend a PCR value");
return rc;
@@ -356,7 +360,7 @@
int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
{
struct tpm2_cmd cmd;
- u32 recd;
+ u32 recd, rlength;
u32 num_bytes;
int err;
int total = 0;
@@ -373,13 +377,19 @@
cmd.header.in = tpm2_getrandom_header;
cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
- err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
- "attempting get random");
+ err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ offsetof(struct tpm2_get_random_out,
+ buffer),
+ 0, "attempting get random");
if (err)
break;
recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
num_bytes);
+ rlength = be32_to_cpu(cmd.header.out.length);
+ if (rlength < offsetof(struct tpm2_get_random_out, buffer) +
+ recd)
+ return -EFAULT;
memcpy(dest, cmd.params.getrandom_out.buffer, recd);
dest += recd;
@@ -394,6 +404,9 @@
(sizeof(struct tpm_input_header) + \
sizeof(struct tpm2_get_tpm_pt_in))
+#define TPM2_GET_TPM_PT_OUT_BODY_SIZE \
+ sizeof(struct tpm2_get_tpm_pt_out)
+
static const struct tpm_input_header tpm2_get_tpm_pt_header = {
.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
.length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
@@ -445,7 +458,7 @@
{
unsigned int blob_len;
struct tpm_buf buf;
- u32 hash;
+ u32 hash, rlength;
int i;
int rc;
@@ -510,7 +523,8 @@
goto out;
}
- rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, "sealing data");
+ rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 4, 0,
+ "sealing data");
if (rc)
goto out;
@@ -519,6 +533,11 @@
rc = -E2BIG;
goto out;
}
+ rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)->header.out.length);
+ if (rlength < TPM_HEADER_SIZE + 4 + blob_len) {
+ rc = -EFAULT;
+ goto out;
+ }
memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
payload->blob_len = blob_len;
@@ -588,7 +607,8 @@
goto out;
}
- rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags, "loading blob");
+ rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 4, flags,
+ "loading blob");
if (!rc)
*blob_handle = be32_to_cpup(
(__be32 *) &buf.data[TPM_HEADER_SIZE]);
@@ -626,7 +646,7 @@
tpm_buf_append_u32(&buf, handle);
- rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags,
+ rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, flags,
"flushing context");
if (rc)
dev_warn(&chip->dev, "0x%08x was not flushed, rc=%d\n", handle,
@@ -657,6 +677,7 @@
u16 data_len;
u8 *data;
int rc;
+ u32 rlength;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
if (rc)
@@ -671,13 +692,21 @@
options->blobauth /* hmac */,
TPM_DIGEST_SIZE);
- rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags, "unsealing");
+ rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 6, flags,
+ "unsealing");
if (rc > 0)
rc = -EPERM;
if (!rc) {
data_len = be16_to_cpup(
(__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
+
+ rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)
+ ->header.out.length);
+ if (rlength < TPM_HEADER_SIZE + 6 + data_len) {
+ rc = -EFAULT;
+ goto out;
+ }
data = &buf.data[TPM_HEADER_SIZE + 6];
memcpy(payload->key, data, data_len - 1);
@@ -685,6 +714,7 @@
payload->migratable = data[data_len - 1];
}
+out:
tpm_buf_destroy(&buf);
return rc;
}
@@ -739,7 +769,8 @@
cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
- rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, desc);
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
+ TPM2_GET_TPM_PT_OUT_BODY_SIZE, 0, desc);
if (!rc)
*value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
@@ -773,7 +804,7 @@
cmd.header.in = tpm2_startup_header;
cmd.params.startup_in.startup_type = cpu_to_be16(startup_type);
- return tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
+ return tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, 0,
"attempting to start the TPM");
}
@@ -802,7 +833,8 @@
cmd.header.in = tpm2_shutdown_header;
cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
- rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, "stopping the TPM");
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, 0,
+ "stopping the TPM");
/* In places where shutdown command is sent there's no much we can do
* except print the error code on a system failure.
@@ -865,7 +897,7 @@
cmd.header.in = tpm2_selftest_header;
cmd.params.selftest_in.full_test = full;
- rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE, 0,
+ rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE, 0, 0,
"continue selftest");
/* At least some prototype chips seem to give RC_TESTING error
@@ -916,7 +948,7 @@
cmd.params.pcrread_in.pcr_select[1] = 0x00;
cmd.params.pcrread_in.pcr_select[2] = 0x00;
- rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, NULL);
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, 0, NULL);
if (rc < 0)
break;
@@ -949,7 +981,7 @@
cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
- rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, NULL);
+ rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, 0, NULL);
if (rc < 0)
return rc;