4.19-stable review patch. If anyone has any objections, please let me know.
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From: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com
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
--- drivers/char/tpm/tpm-interface.c | 3 ++- drivers/char/tpm/tpm2-cmd.c | 4 +++- 2 files changed, 5 insertions(+), 2 deletions(-)
--- 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 }
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; --- 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 *chi &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; }