tpm: fix a race condition in tpm2_unseal_trusted()
Unseal and load operations should be done as an atomic operation. This
commit introduces unlocked tpm_transmit() so that tpm2_unseal_trusted()
can do the locking by itself.
Fixes: 0fe5480303a1 ("keys, trusted: seal/unseal with TPM 2.0 chips")
Cc: stable@vger.kernel.org
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 1abe2d7..aef20ee 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -330,8 +330,8 @@
/*
* Internal kernel interface to transmit TPM commands
*/
-ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
- size_t bufsiz)
+ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
+ unsigned int flags)
{
ssize_t rc;
u32 count, ordinal;
@@ -350,7 +350,8 @@
return -E2BIG;
}
- mutex_lock(&chip->tpm_mutex);
+ if (!(flags & TPM_TRANSMIT_UNLOCKED))
+ mutex_lock(&chip->tpm_mutex);
rc = chip->ops->send(chip, (u8 *) buf, count);
if (rc < 0) {
@@ -393,20 +394,21 @@
dev_err(&chip->dev,
"tpm_transmit: tpm_recv: error %zd\n", rc);
out:
- mutex_unlock(&chip->tpm_mutex);
+ if (!(flags & TPM_TRANSMIT_UNLOCKED))
+ mutex_unlock(&chip->tpm_mutex);
return rc;
}
#define TPM_DIGEST_SIZE 20
#define TPM_RET_CODE_IDX 6
-ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,
- int len, const char *desc)
+ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
+ int len, unsigned int flags, const char *desc)
{
- struct tpm_output_header *header;
+ const struct tpm_output_header *header;
int err;
- len = tpm_transmit(chip, (u8 *) cmd, len);
+ len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
if (len < 0)
return len;
else if (len < TPM_HEADER_SIZE)
@@ -453,7 +455,8 @@
tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
tpm_cmd.params.getcap_in.subcap = subcap_id;
}
- rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
+ rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
+ desc);
if (!rc)
*cap = tpm_cmd.params.getcap_out.cap;
return rc;
@@ -469,7 +472,7 @@
tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
- rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
+ rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
"attempting to determine the timeouts");
}
EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
@@ -490,7 +493,7 @@
start_cmd.header.in = tpm_startup_header;
start_cmd.params.startup_in.startup_type = startup_type;
- return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
+ return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
"attempting to start the TPM");
}
@@ -521,7 +524,8 @@
tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
- rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
+ rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
+ NULL);
if (rc == TPM_ERR_INVALID_POSTINIT) {
/* The TPM is not started, we are the first to talk to it.
@@ -535,7 +539,7 @@
tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
- NULL);
+ 0, NULL);
}
if (rc) {
dev_err(&chip->dev,
@@ -596,7 +600,7 @@
tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
- rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
+ rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
"attempting to determine the durations");
if (rc)
return rc;
@@ -652,7 +656,7 @@
struct tpm_cmd_t cmd;
cmd.header.in = continue_selftest_header;
- rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
+ rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
"continue selftest");
return rc;
}
@@ -672,7 +676,7 @@
cmd.header.in = pcrread_header;
cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
- rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
+ rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
"attempting to read a pcr value");
if (rc == 0)
@@ -770,7 +774,7 @@
cmd.header.in = pcrextend_header;
cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
- rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
+ rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
"attempting extend a PCR value");
tpm_put_ops(chip);
@@ -809,7 +813,7 @@
/* Attempt to read a PCR value */
cmd.header.in = pcrread_header;
cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
- rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
+ rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE, 0);
/* Some buggy TPMs will not respond to tpm_tis_ready() for
* around 300ms while the self test is ongoing, keep trying
* until the self test duration expires. */
@@ -879,7 +883,7 @@
if (chip == NULL)
return -ENODEV;
- rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
+ rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
tpm_put_ops(chip);
return rc;
@@ -981,14 +985,15 @@
cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
TPM_DIGEST_SIZE);
- rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
+ rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
"extending dummy pcr before suspend");
}
/* now do the actual savestate */
for (try = 0; try < TPM_RETRY; try++) {
cmd.header.in = savestate_header;
- rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
+ rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
+ NULL);
/*
* If the TPM indicates that it is too busy to respond to
@@ -1072,8 +1077,8 @@
tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
err = tpm_transmit_cmd(chip, &tpm_cmd,
- TPM_GETRANDOM_RESULT_SIZE + num_bytes,
- "attempting get random");
+ TPM_GETRANDOM_RESULT_SIZE + num_bytes,
+ 0, "attempting get random");
if (err)
break;