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author | Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> | 2018-09-03 04:01:26 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-13 22:08:48 +0300 |
commit | c6d2e2023c2c0dd91cf8ba18fe2fa888aceb0f88 (patch) | |
tree | d2c69b8d6317cc6fa1e40f04032b51f681dd082a | |
parent | e6d2f788cb714c1675645813feee23306ad39e73 (diff) | |
download | linux-c6d2e2023c2c0dd91cf8ba18fe2fa888aceb0f88.tar.xz |
tpm: fix response size validation in tpm_get_random()
commit 84b59f6487d82d3ab4247a099aba66d4d17e8b08 upstream.
When checking whether the response is large enough to be able to contain
the received random bytes in tpm_get_random() and tpm2_get_random(),
they fail to take account the header size, which should be added to the
minimum size. This commit fixes this issue.
Cc: stable@vger.kernel.org
Fixes: c659af78eb7b ("tpm: Check size of response before accessing data")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/char/tpm/tpm-interface.c | 3 | ||||
-rw-r--r-- | drivers/char/tpm/tpm2-cmd.c | 4 |
2 files changed, 5 insertions, 2 deletions
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 9f61106502a9..7d958ff426e0 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1322,7 +1322,8 @@ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max) } rlength = be32_to_cpu(tpm_cmd.header.out.length); - if (rlength < offsetof(struct tpm_getrandom_out, rng_data) + + if (rlength < TPM_HEADER_SIZE + + offsetof(struct tpm_getrandom_out, rng_data) + recd) { total = -EFAULT; break; diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index c31b490bd41d..3acf4fd4e5a5 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -329,7 +329,9 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) &buf.data[TPM_HEADER_SIZE]; recd = min_t(u32, be16_to_cpu(out->size), num_bytes); if (tpm_buf_length(&buf) < - offsetof(struct tpm2_get_random_out, buffer) + recd) { + TPM_HEADER_SIZE + + offsetof(struct tpm2_get_random_out, buffer) + + recd) { err = -EFAULT; goto out; } |