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authorJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2017-02-14 22:57:42 +0300
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2017-04-03 22:46:01 +0300
commita147918e79c3a239be59358af659ea9f0959538b (patch)
tree2502fcfffc23e84d930669accc4c60b0da138c2f /drivers/char/tpm/tpm-interface.c
parent38eb24ebb01f875f812aa869c4cd62959510111c (diff)
downloadlinux-a147918e79c3a239be59358af659ea9f0959538b.tar.xz
tpm: move length validation to tpm_transmit()
Check that the length matches the length reported by the response header already in tpm_transmit() to improve validation. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com> Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Diffstat (limited to 'drivers/char/tpm/tpm-interface.c')
-rw-r--r--drivers/char/tpm/tpm-interface.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index bd2128e0b56c..708d3563ee7d 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -343,6 +343,7 @@ EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
unsigned int flags)
{
+ const struct tpm_output_header *header = (void *)buf;
ssize_t rc;
u32 count, ordinal;
unsigned long stop;
@@ -406,9 +407,18 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
out_recv:
rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
- if (rc < 0)
+ if (rc < 0) {
dev_err(&chip->dev,
"tpm_transmit: tpm_recv: error %zd\n", rc);
+ goto out;
+ } else if (rc < TPM_HEADER_SIZE) {
+ rc = -EFAULT;
+ goto out;
+ }
+
+ if (rc != be32_to_cpu(header->length))
+ goto out;
+
out:
if (chip->dev.parent)
pm_runtime_put_sync(chip->dev.parent);
@@ -438,19 +448,13 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *buf,
size_t bufsiz, size_t min_rsp_body_length,
unsigned int flags, const char *desc)
{
- const struct tpm_output_header *header;
+ const struct tpm_output_header *header = buf;
int err;
ssize_t len;
len = tpm_transmit(chip, (const u8 *)buf, bufsiz, flags);
if (len < 0)
return len;
- else if (len < TPM_HEADER_SIZE)
- return -EFAULT;
-
- header = buf;
- if (len != be32_to_cpu(header->length))
- return -EFAULT;
err = be32_to_cpu(header->return_code);
if (err != 0 && desc)