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 --- For v4.14 and v4.18. Fixed a merge conflict. drivers/char/tpm/tpm-interface.c | 3 ++- drivers/char/tpm/tpm2-cmd.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index e8822b3d10e1..a107ee2466da 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1323,7 +1323,8 @@ 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 d31b09099216..79b00bc4a7c2 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -371,7 +371,8 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max) 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) + + if (rlength < TPM_HEADER_SIZE + + offsetof(struct tpm2_get_random_out, buffer) + recd) return -EFAULT; memcpy(dest, cmd.params.getrandom_out.buffer, recd);